Alert archive / New Jersey / Heat Advisories in 2025

Heat Advisory 9, NWS Philadelphia/Mount Holly

July 28, 202510 counties in Pennsylvania; 12 counties in New Jersey; New Castle County, Delaware

NWS Philadelphia/Mount Holly issued this heat advisory at Jul 28, 2025, 3:00 AM EDT for 10 counties in Pennsylvania; 12 counties in New Jersey; New Castle County, Delaware. It took effect at Jul 28, 2025, 11:00 AM EDT. It was in force for 57 hr.

The area

The counties it named.

The facts

Issued
Jul 28, 2025, 3:00 AM EDT (07:00 UTC)
In effect from
Jul 28, 2025, 11:00 AM EDT
Expired
Jul 30, 2025, 8:00 PM EDT
In force
57 hr
Issued by
NWS Philadelphia/Mount Holly
All 23 counties

New Castle County, DE, Burlington County, NJ, Camden County, NJ, Gloucester County, NJ, Hunterdon County, NJ, Mercer County, NJ, Middlesex County, NJ, Monmouth County, NJ, Morris County, NJ, Ocean County, NJ, Somerset County, NJ, Sussex County, NJ, Warren County, NJ, Berks County, PA, Bucks County, PA, Carbon County, PA, Chester County, PA, Delaware County, PA, Lehigh County, PA, Monroe County, PA, Montgomery County, PA, Northampton County, PA, Philadelphia County, PA

The radar

The Philadelphia radar (KDIX), 71 km from the middle of the area, began a volume at 07:01 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

The nearest sounding before it

Brookhaven, NY (KOKX), launched 00:00Z, 7.0 hours before the alert went out and 194 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-pSkew-T log-p diagram, Brookhaven, NY at 00:00Z on 2025-07-28Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 728 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Brookhaven, NY at 00:00Z on 2025-07-28The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 135 square meters per square second.19395878Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
728 J/kg
Mixed-layer CIN
-21 J/kg
Mixed-layer LCL
563 m above ground
0-6 km bulk shear
31 kt
0-1 km storm-relative helicity
135 m²/s²
0-3 km storm-relative helicity
171 m²/s²
Significant tornado parameter
0.4
Supercell composite
3.7

Open this sounding in Storm Lab

The text

As transmitted.

752 
WWUS71 KPHI 280700
NPWPHI

URGENT - WEATHER MESSAGE
National Weather Service Mount Holly NJ
300 AM EDT Mon Jul 28 2025

DEZ001-NJZ008>010-012-013-015-017>020-027-PAZ070-071-103>106-282000-
/O.NEW.KPHI.HT.Y.0009.250728T1500Z-250731T0000Z/
New Castle-Morris-Hunterdon-Somerset-Middlesex-Western Monmouth-
Mercer-Gloucester-Camden-Northwestern Burlington-Ocean-
Southeastern Burlington-Delaware-Philadelphia-Western Montgomery-
Eastern Montgomery-Upper Bucks-Lower Bucks-
Including the cities of Moorestown, Pottstown, Wilmington, Media,
Norristown, Jackson, Freehold, Mount Holly, Wharton State Forest,
Collegeville, Cherry Hill, Perkasie, Philadelphia, Flemington,
Chalfont, Lansdale, Doylestown, Camden, Glassboro, Morristown,
Trenton, New Brunswick, Somerville, and Morrisville
300 AM EDT Mon Jul 28 2025

...HEAT ADVISORY IN EFFECT FROM 11 AM THIS MORNING TO 8 PM EDT 
WEDNESDAY...

* WHAT...Heat index values up to 104 degrees expected.

* WHERE...Portions of northern Delaware, central, northern, 
  northwest, and southern New Jersey, and southeast Pennsylvania.

* WHEN...From 11 AM this morning to 8 PM EDT Wednesday.

* IMPACTS...Hot temperatures and high humidity may cause heat 
  illnesses.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Drink plenty of fluids, stay in an air-conditioned room, stay out of 
the sun, and check up on relatives and neighbors.

Take extra precautions when outside. Wear lightweight and loose 
fitting clothing. Try to limit strenuous activities to early morning 
or evening. Take action when you see symptoms of heat exhaustion and 
heat stroke.

&&

$$

NJZ001-007-PAZ054-055-060>062-101-102-282000-
/O.NEW.KPHI.HT.Y.0009.250729T1500Z-250731T0000Z/
Sussex-Warren-Carbon-Monroe-Berks-Lehigh-Northampton-Western
Chester-Eastern Chester-
Including the cities of Kennett Square, Allentown, Stroudsburg,
Oxford, Easton, Newton, Jim Thorpe, Washington, Honey Brook,
Bethlehem, West Chester, and Reading
300 AM EDT Mon Jul 28 2025

...HEAT ADVISORY IN EFFECT FROM 11 AM TUESDAY TO 8 PM EDT 
WEDNESDAY...

* WHAT...Heat index values up to 103 degrees expected.

* WHERE...In New Jersey, Sussex and Warren Counties. In 
  Pennsylvania, Berks, Lehigh, Northampton, Carbon, Monroe, Eastern 
  Chester, and Western Chester Counties.

* WHEN...From 11 AM Tuesday to 8 PM EDT Wednesday.

* IMPACTS...Hot temperatures and high humidity may cause heat 
  illnesses.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Drink plenty of fluids, stay in an air-conditioned room, stay out of 
the sun, and check up on relatives and neighbors.

To reduce risk during outdoor work, the Occupational Safety and 
Health Administration recommends scheduling frequent rest breaks in 
shaded or air conditioned environments. Anyone overcome by heat 
should be moved to a cool and shaded location. Heat stroke is an 
emergency! Call 9 1 1.

&&

$$

NJZ014-026-282000-
/O.NEW.KPHI.HT.Y.0009.250729T1500Z-250731T0000Z/
Eastern Monmouth-Coastal Ocean-
Including the cities of Long Beach Island and Sandy Hook
300 AM EDT Mon Jul 28 2025

...HEAT ADVISORY IN EFFECT FROM 11 AM TUESDAY TO 8 PM EDT 
WEDNESDAY...

* WHAT...Heat index values up to 102 degrees expected.

* WHERE...Eastern Monmouth and Coastal Ocean Counties.

* WHEN...From 11 AM Tuesday to 8 PM EDT Wednesday.

* IMPACTS...Hot temperatures and high humidity may cause heat 
  illnesses.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Drink plenty of fluids, stay in an air-conditioned room, stay out of 
the sun, and check up on relatives and neighbors.

Take extra precautions when outside. Wear lightweight and loose 
fitting clothing. Try to limit strenuous activities to early morning 
or evening. Take action when you see symptoms of heat exhaustion and 
heat stroke.

&&

$$

AKL
6 follow-up statements
562 
WWUS71 KPHI 281825
NPWPHI

URGENT - WEATHER MESSAGE
National Weather Service Mount Holly NJ
225 PM EDT Mon Jul 28 2025

DEZ001-NJZ008>010-012-013-015-017>020-027-PAZ070-071-103>106-291000-
/O.CON.KPHI.HT.Y.0009.000000T0000Z-250731T0000Z/
New Castle-Morris-Hunterdon-Somerset-Middlesex-Western Monmouth-
Mercer-Gloucester-Camden-Northwestern Burlington-Ocean-
Southeastern Burlington-Delaware-Philadelphia-Western Montgomery-
Eastern Montgomery-Upper Bucks-Lower Bucks-
Including the cities of Trenton, Chalfont, Wilmington, Glassboro,
Freehold, Morristown, Camden, Lansdale, Doylestown, Jackson,
Flemington, Norristown, Pottstown, Somerville, New Brunswick,
Morrisville, Collegeville, Mount Holly, Media, Wharton State
Forest, Philadelphia, Moorestown, Perkasie, and Cherry Hill
225 PM EDT Mon Jul 28 2025

...HEAT ADVISORY REMAINS IN EFFECT UNTIL 8 PM EDT WEDNESDAY...

* WHAT...Heat index values up to 104.

* WHERE...Portions of northern Delaware, New Jersey, and southeast 
  Pennsylvania.

* WHEN...Until 8 PM EDT Wednesday.

* IMPACTS...Hot temperatures and high humidity may cause heat 
  illnesses.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Drink plenty of fluids, stay in an air-conditioned room, stay out of 
the sun, and check up on relatives and neighbors.

Take extra precautions when outside. Wear lightweight and loose 
fitting clothing. Try to limit strenuous activities to early morning 
or evening. Take action when you see symptoms of heat exhaustion and 
heat stroke.

To reduce risk during outdoor work, the Occupational Safety and 
Health Administration recommends scheduling frequent rest breaks in 
shaded or air conditioned environments. Anyone overcome by heat 
should be moved to a cool and shaded location. Heat stroke is an 
emergency! Call 9 1 1.

&&

$$

NJZ001-007-PAZ054-055-060>062-101-102-291000-
/O.CON.KPHI.HT.Y.0009.250729T1500Z-250731T0000Z/
Sussex-Warren-Carbon-Monroe-Berks-Lehigh-Northampton-Western
Chester-Eastern Chester-
Including the cities of Oxford, Newton, Stroudsburg, Allentown,
West Chester, Washington, Easton, Bethlehem, Jim Thorpe, Honey
Brook, Kennett Square, and Reading
225 PM EDT Mon Jul 28 2025

...HEAT ADVISORY REMAINS IN EFFECT FROM 11 AM TUESDAY TO 8 PM EDT 
WEDNESDAY...

* WHAT...Heat index values up to 102 expected.

* WHERE...In New Jersey, Sussex and Warren Counties. In 
  Pennsylvania, Berks, Lehigh, Northampton, Carbon, Monroe, Eastern 
  Chester, and Western Chester Counties.

* WHEN...From 11 AM Tuesday to 8 PM EDT Wednesday.

* IMPACTS...Hot temperatures and high humidity may cause heat 
  illnesses.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Drink plenty of fluids, stay in an air-conditioned room, stay out of 
the sun, and check up on relatives and neighbors.

Take extra precautions when outside. Wear lightweight and loose 
fitting clothing. Try to limit strenuous activities to early morning 
or evening. Take action when you see symptoms of heat exhaustion and 
heat stroke.

To reduce risk during outdoor work, the Occupational Safety and 
Health Administration recommends scheduling frequent rest breaks in 
shaded or air conditioned environments. Anyone overcome by heat 
should be moved to a cool and shaded location. Heat stroke is an 
emergency! Call 9 1 1.

&&

$$

NJZ014-026-291000-
/O.CON.KPHI.HT.Y.0009.250729T1500Z-250731T0000Z/
Eastern Monmouth-Coastal Ocean-
Including the cities of Long Beach Island and Sandy Hook
225 PM EDT Mon Jul 28 2025

...HEAT ADVISORY REMAINS IN EFFECT FROM 11 AM TUESDAY TO 8 PM EDT 
WEDNESDAY...

* WHAT...Heat index values up to 102 expected.

* WHERE...Eastern Monmouth and Coastal Ocean Counties.

* WHEN...From 11 AM Tuesday to 8 PM EDT Wednesday.

* IMPACTS...Hot temperatures and high humidity may cause heat 
  illnesses.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Drink plenty of fluids, stay in an air-conditioned room, stay out of 
the sun, and check up on relatives and neighbors.

Take extra precautions when outside. Wear lightweight and loose 
fitting clothing. Try to limit strenuous activities to early morning 
or evening. Take action when you see symptoms of heat exhaustion and 
heat stroke.

To reduce risk during outdoor work, the Occupational Safety and 
Health Administration recommends scheduling frequent rest breaks in 
shaded or air conditioned environments. Anyone overcome by heat 
should be moved to a cool and shaded location. Heat stroke is an 
emergency! Call 9 1 1.

&&

$$

MPS
516 
WWUS71 KPHI 290812
NPWPHI

URGENT - WEATHER MESSAGE
National Weather Service Mount Holly NJ
412 AM EDT Tue Jul 29 2025

DEZ001-NJZ008>010-012-013-015-017>020-027-PAZ070-071-103>106-292100-
/O.CON.KPHI.HT.Y.0009.000000T0000Z-250731T0000Z/
New Castle-Morris-Hunterdon-Somerset-Middlesex-Western Monmouth-
Mercer-Gloucester-Camden-Northwestern Burlington-Ocean-
Southeastern Burlington-Delaware-Philadelphia-Western Montgomery-
Eastern Montgomery-Upper Bucks-Lower Bucks-
Including the cities of Camden, New Brunswick, Wilmington,
Perkasie, Freehold, Cherry Hill, Lansdale, Chalfont, Glassboro,
Moorestown, Doylestown, Jackson, Philadelphia, Somerville,
Wharton State Forest, Trenton, Pottstown, Mount Holly,
Norristown, Flemington, Morristown, Morrisville, Collegeville,
and Media
412 AM EDT Tue Jul 29 2025

...HEAT ADVISORY REMAINS IN EFFECT UNTIL 8 PM EDT WEDNESDAY...

* WHAT...Heat index values up to 104 degrees expected.

* WHERE...Portions of northern Delaware, central, northern, 
  northwest, and southern New Jersey, and southeast Pennsylvania.

* WHEN...Until 8 PM EDT Wednesday.

* IMPACTS...Hot temperatures and high humidity may cause heat 
  illnesses.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Drink plenty of fluids, stay in an air-conditioned room, stay out of 
the sun, and check up on relatives and neighbors.

Take extra precautions when outside. Wear lightweight and loose 
fitting clothing. Try to limit strenuous activities to early morning 
or evening. Take action when you see symptoms of heat exhaustion and 
heat stroke.

To reduce risk during outdoor work, the Occupational Safety and 
Health Administration recommends scheduling frequent rest breaks in 
shaded or air conditioned environments. Anyone overcome by heat 
should be moved to a cool and shaded location. Heat stroke is an 
emergency! Call 9 1 1.

&&

$$

NJZ001-007-PAZ054-055-060>062-101-102-292100-
/O.CON.KPHI.HT.Y.0009.250729T1500Z-250731T0000Z/
Sussex-Warren-Carbon-Monroe-Berks-Lehigh-Northampton-Western
Chester-Eastern Chester-
Including the cities of Jim Thorpe, Easton, Newton, Stroudsburg,
Allentown, Honey Brook, Bethlehem, Kennett Square, Washington,
Reading, Oxford, and West Chester
412 AM EDT Tue Jul 29 2025

...HEAT ADVISORY REMAINS IN EFFECT FROM 11 AM THIS MORNING TO 8 PM 
EDT WEDNESDAY...

* WHAT...Heat index values up to 103 degrees expected.

* WHERE...In New Jersey, Sussex and Warren Counties. In 
  Pennsylvania, Berks, Lehigh, Northampton, Carbon, Monroe, Eastern 
  Chester, and Western Chester Counties.

* WHEN...From 11 AM this morning to 8 PM EDT Wednesday.

* IMPACTS...Hot temperatures and high humidity may cause heat 
  illnesses.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Drink plenty of fluids, stay in an air-conditioned room, stay out of 
the sun, and check up on relatives and neighbors.

Take extra precautions when outside. Wear lightweight and loose 
fitting clothing. Try to limit strenuous activities to early morning 
or evening. Take action when you see symptoms of heat exhaustion and 
heat stroke.

To reduce risk during outdoor work, the Occupational Safety and 
Health Administration recommends scheduling frequent rest breaks in 
shaded or air conditioned environments. Anyone overcome by heat 
should be moved to a cool and shaded location. Heat stroke is an 
emergency! Call 9 1 1.

&&

$$

NJZ014-026-292100-
/O.CON.KPHI.HT.Y.0009.250729T1500Z-250731T0000Z/
Eastern Monmouth-Coastal Ocean-
Including the cities of Sandy Hook and Long Beach Island
412 AM EDT Tue Jul 29 2025

...HEAT ADVISORY REMAINS IN EFFECT FROM 11 AM THIS MORNING TO 8 PM 
EDT WEDNESDAY...

* WHAT...Heat index values up to 102 degrees expected.

* WHERE...Eastern Monmouth and Coastal Ocean Counties.

* WHEN...From 11 AM this morning to 8 PM EDT Wednesday.

* IMPACTS...Hot temperatures and high humidity may cause heat 
  illnesses.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Drink plenty of fluids, stay in an air-conditioned room, stay out of 
the sun, and check up on relatives and neighbors.

Take extra precautions when outside. Wear lightweight and loose 
fitting clothing. Try to limit strenuous activities to early morning 
or evening. Take action when you see symptoms of heat exhaustion and 
heat stroke.

To reduce risk during outdoor work, the Occupational Safety and 
Health Administration recommends scheduling frequent rest breaks in 
shaded or air conditioned environments. Anyone overcome by heat 
should be moved to a cool and shaded location. Heat stroke is an 
emergency! Call 9 1 1.

&&

$$

Staarmann
368 
WWUS71 KPHI 291846
NPWPHI

URGENT - WEATHER MESSAGE
National Weather Service Mount Holly NJ
246 PM EDT Tue Jul 29 2025

DEZ001-NJZ008>010-012-013-015-017>020-027-PAZ070-071-103>106-301000-
/O.CON.KPHI.HT.Y.0009.000000T0000Z-250731T0000Z/
New Castle-Morris-Hunterdon-Somerset-Middlesex-Western Monmouth-
Mercer-Gloucester-Camden-Northwestern Burlington-Ocean-
Southeastern Burlington-Delaware-Philadelphia-Western Montgomery-
Eastern Montgomery-Upper Bucks-Lower Bucks-
Including the cities of Moorestown, New Brunswick, Chalfont,
Trenton, Cherry Hill, Collegeville, Glassboro, Doylestown,
Freehold, Philadelphia, Somerville, Media, Wilmington, Pottstown,
Perkasie, Morristown, Jackson, Wharton State Forest, Camden,
Lansdale, Norristown, Mount Holly, Morrisville, and Flemington
246 PM EDT Tue Jul 29 2025

...HEAT ADVISORY REMAINS IN EFFECT UNTIL 8 PM EDT WEDNESDAY...

* WHAT...Heat index values up to 104.

* WHERE...Portions of northern Delaware, central, northern, 
  northwest, and southern New Jersey, and southeast Pennsylvania.

* WHEN...Until 8 PM EDT Wednesday.

* IMPACTS...Hot temperatures and high humidity may cause heat 
  illnesses.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Drink plenty of fluids, stay in an air-conditioned room, stay out of 
the sun, and check up on relatives and neighbors.

Take extra precautions when outside. Wear lightweight and loose 
fitting clothing. Try to limit strenuous activities to early morning 
or evening. Take action when you see symptoms of heat exhaustion and 
heat stroke.

To reduce risk during outdoor work, the Occupational Safety and 
Health Administration recommends scheduling frequent rest breaks in 
shaded or air conditioned environments. Anyone overcome by heat 
should be moved to a cool and shaded location. Heat stroke is an 
emergency! Call 9 1 1.

&&

$$

NJZ001-007-PAZ054-055-060>062-101-102-301000-
/O.CON.KPHI.HT.Y.0009.000000T0000Z-250731T0000Z/
Sussex-Warren-Carbon-Monroe-Berks-Lehigh-Northampton-Western
Chester-Eastern Chester-
Including the cities of Kennett Square, Newton, Jim Thorpe,
Bethlehem, Washington, Easton, Oxford, Allentown, Reading, West
Chester, Honey Brook, and Stroudsburg
246 PM EDT Tue Jul 29 2025

...HEAT ADVISORY REMAINS IN EFFECT UNTIL 8 PM EDT WEDNESDAY...

* WHAT...Heat index values up to 103.

* WHERE...In New Jersey, Sussex and Warren Counties. In 
  Pennsylvania, Berks, Lehigh, Northampton, Carbon, Monroe, Eastern 
  Chester, and Western Chester Counties.

* WHEN...Until 8 PM EDT Wednesday.

* IMPACTS...Hot temperatures and high humidity may cause heat 
  illnesses.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Drink plenty of fluids, stay in an air-conditioned room, stay out of 
the sun, and check up on relatives and neighbors.

Take extra precautions when outside. Wear lightweight and loose 
fitting clothing. Try to limit strenuous activities to early morning 
or evening. Take action when you see symptoms of heat exhaustion and 
heat stroke.

To reduce risk during outdoor work, the Occupational Safety and 
Health Administration recommends scheduling frequent rest breaks in 
shaded or air conditioned environments. Anyone overcome by heat 
should be moved to a cool and shaded location. Heat stroke is an 
emergency! Call 9 1 1.

&&

$$

NJZ014-026-301000-
/O.CON.KPHI.HT.Y.0009.000000T0000Z-250731T0000Z/
Eastern Monmouth-Coastal Ocean-
Including the cities of Sandy Hook and Long Beach Island
246 PM EDT Tue Jul 29 2025

...HEAT ADVISORY REMAINS IN EFFECT UNTIL 8 PM EDT WEDNESDAY...

* WHAT...Heat index values up to 102.

* WHERE...Eastern Monmouth and Coastal Ocean Counties.

* WHEN...Until 8 PM EDT Wednesday.

* IMPACTS...Hot temperatures and high humidity may cause heat 
  illnesses.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Drink plenty of fluids, stay in an air-conditioned room, stay out of 
the sun, and check up on relatives and neighbors.

Take extra precautions when outside. Wear lightweight and loose 
fitting clothing. Try to limit strenuous activities to early morning 
or evening. Take action when you see symptoms of heat exhaustion and 
heat stroke.

To reduce risk during outdoor work, the Occupational Safety and 
Health Administration recommends scheduling frequent rest breaks in 
shaded or air conditioned environments. Anyone overcome by heat 
should be moved to a cool and shaded location. Heat stroke is an 
emergency! Call 9 1 1.

&&

$$

PO
251 
WWUS71 KPHI 300801
NPWPHI

URGENT - WEATHER MESSAGE
National Weather Service Mount Holly NJ
401 AM EDT Wed Jul 30 2025

DEZ001-NJZ008>010-012-013-015-017>020-027-PAZ070-071-103>106-310000-
/O.CON.KPHI.HT.Y.0009.000000T0000Z-250731T0000Z/
New Castle-Morris-Hunterdon-Somerset-Middlesex-Western Monmouth-
Mercer-Gloucester-Camden-Northwestern Burlington-Ocean-
Southeastern Burlington-Delaware-Philadelphia-Western Montgomery-
Eastern Montgomery-Upper Bucks-Lower Bucks-
Including the cities of New Brunswick, Trenton, Flemington,
Perkasie, Mount Holly, Glassboro, Doylestown, Morristown,
Wilmington, Pottstown, Norristown, Cherry Hill, Freehold, Wharton
State Forest, Media, Morrisville, Philadelphia, Chalfont, Camden,
Lansdale, Moorestown, Jackson, Somerville, and Collegeville
401 AM EDT Wed Jul 30 2025

...HEAT ADVISORY REMAINS IN EFFECT UNTIL 8 PM EDT THIS EVENING...

* WHAT...Heat index values up to 104 degrees expected.

* WHERE...Portions of northern Delaware, central, northern, 
  northwest, and southern New Jersey, and southeast Pennsylvania.

* WHEN...Until 8 PM EDT this evening.

* IMPACTS...Hot temperatures and high humidity may cause heat 
  illnesses.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Drink plenty of fluids, stay in an air-conditioned room, stay out of 
the sun, and check up on relatives and neighbors.

Take extra precautions when outside. Wear lightweight and loose 
fitting clothing. Try to limit strenuous activities to early morning 
or evening. Take action when you see symptoms of heat exhaustion and 
heat stroke.

To reduce risk during outdoor work, the Occupational Safety and 
Health Administration recommends scheduling frequent rest breaks in 
shaded or air conditioned environments. Anyone overcome by heat 
should be moved to a cool and shaded location. Heat stroke is an 
emergency! Call 9 1 1.

&&

$$

NJZ001-007-PAZ054-055-060>062-101-102-310000-
/O.CON.KPHI.HT.Y.0009.000000T0000Z-250731T0000Z/
Sussex-Warren-Carbon-Monroe-Berks-Lehigh-Northampton-Western
Chester-Eastern Chester-
Including the cities of Allentown, West Chester, Reading,
Bethlehem, Jim Thorpe, Washington, Oxford, Stroudsburg, Honey
Brook, Kennett Square, Newton, and Easton
401 AM EDT Wed Jul 30 2025

...HEAT ADVISORY REMAINS IN EFFECT UNTIL 8 PM EDT THIS EVENING...

* WHAT...Heat index values up to 103 degrees expected.

* WHERE...In New Jersey, Sussex and Warren Counties. In 
  Pennsylvania, Berks, Lehigh, Northampton, Carbon, Monroe, Eastern 
  Chester, and Western Chester Counties.

* WHEN...Until 8 PM EDT this evening.

* IMPACTS...Hot temperatures and high humidity may cause heat 
  illnesses.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Drink plenty of fluids, stay in an air-conditioned room, stay out of 
the sun, and check up on relatives and neighbors.

Take extra precautions when outside. Wear lightweight and loose 
fitting clothing. Try to limit strenuous activities to early morning 
or evening. Take action when you see symptoms of heat exhaustion and 
heat stroke.

To reduce risk during outdoor work, the Occupational Safety and 
Health Administration recommends scheduling frequent rest breaks in 
shaded or air conditioned environments. Anyone overcome by heat 
should be moved to a cool and shaded location. Heat stroke is an 
emergency! Call 9 1 1.

&&

$$

NJZ014-026-310000-
/O.CON.KPHI.HT.Y.0009.000000T0000Z-250731T0000Z/
Eastern Monmouth-Coastal Ocean-
Including the cities of Long Beach Island and Sandy Hook
401 AM EDT Wed Jul 30 2025

...HEAT ADVISORY REMAINS IN EFFECT UNTIL 8 PM EDT THIS EVENING...

* WHAT...Heat index values up to 102 degrees expected.

* WHERE...Eastern Monmouth and Coastal Ocean Counties.

* WHEN...Until 8 PM EDT this evening.

* IMPACTS...Hot temperatures and high humidity may cause heat 
  illnesses.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Drink plenty of fluids, stay in an air-conditioned room, stay out of 
the sun, and check up on relatives and neighbors.

Take extra precautions when outside. Wear lightweight and loose 
fitting clothing. Try to limit strenuous activities to early morning 
or evening. Take action when you see symptoms of heat exhaustion and 
heat stroke.

To reduce risk during outdoor work, the Occupational Safety and 
Health Administration recommends scheduling frequent rest breaks in 
shaded or air conditioned environments. Anyone overcome by heat 
should be moved to a cool and shaded location. Heat stroke is an 
emergency! Call 9 1 1.

&&

$$

Staarmann
565 
WWUS71 KPHI 301811
NPWPHI

URGENT - WEATHER MESSAGE
National Weather Service Mount Holly NJ
211 PM EDT Wed Jul 30 2025

DEZ001-NJZ008>010-012-013-015-017>020-027-PAZ070-071-103>106-310000-
/O.CON.KPHI.HT.Y.0009.000000T0000Z-250731T0000Z/
New Castle-Morris-Hunterdon-Somerset-Middlesex-Western Monmouth-
Mercer-Gloucester-Camden-Northwestern Burlington-Ocean-
Southeastern Burlington-Delaware-Philadelphia-Western Montgomery-
Eastern Montgomery-Upper Bucks-Lower Bucks-
Including the cities of Moorestown, Pottstown, Jackson, Trenton,
Perkasie, Doylestown, Morrisville, Glassboro, Norristown, Camden,
Somerville, Cherry Hill, Mount Holly, New Brunswick, Lansdale,
Morristown, Media, Flemington, Chalfont, Wilmington, Freehold,
Philadelphia, Collegeville, and Wharton State Forest
211 PM EDT Wed Jul 30 2025

...HEAT ADVISORY REMAINS IN EFFECT UNTIL 8 PM EDT THIS EVENING...

* WHAT...Heat index values up to 105.

* WHERE...Portions of northern Delaware, New Jersey, and southeast 
  Pennsylvania.

* WHEN...Until 8 PM EDT this evening.

* IMPACTS...Hot temperatures and high humidity may cause heat 
  illnesses.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Drink plenty of fluids, stay in an air-conditioned room, stay out of 
the sun, and check up on relatives and neighbors.

Take extra precautions when outside. Wear lightweight and loose 
fitting clothing. Try to limit strenuous activities to early morning 
or evening. Take action when you see symptoms of heat exhaustion and 
heat stroke.

To reduce risk during outdoor work, the Occupational Safety and 
Health Administration recommends scheduling frequent rest breaks in 
shaded or air conditioned environments. Anyone overcome by heat 
should be moved to a cool and shaded location. Heat stroke is an 
emergency! Call 9 1 1.

&&

$$

NJZ001-007-PAZ054-055-060>062-101-102-310000-
/O.CON.KPHI.HT.Y.0009.000000T0000Z-250731T0000Z/
Sussex-Warren-Carbon-Monroe-Berks-Lehigh-Northampton-Western
Chester-Eastern Chester-
Including the cities of West Chester, Stroudsburg, Oxford, Jim
Thorpe, Kennett Square, Allentown, Honey Brook, Washington,
Easton, Reading, Bethlehem, and Newton
211 PM EDT Wed Jul 30 2025

...HEAT ADVISORY REMAINS IN EFFECT UNTIL 8 PM EDT THIS EVENING...

* WHAT...Heat index values up to 103.

* WHERE...In New Jersey, Sussex and Warren Counties. In 
  Pennsylvania, Berks, Lehigh, Northampton, Carbon, Monroe, Eastern 
  Chester, and Western Chester Counties.

* WHEN...Until 8 PM EDT this evening.

* IMPACTS...Hot temperatures and high humidity may cause heat 
  illnesses.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Drink plenty of fluids, stay in an air-conditioned room, stay out of 
the sun, and check up on relatives and neighbors.

Take extra precautions when outside. Wear lightweight and loose 
fitting clothing. Try to limit strenuous activities to early morning 
or evening. Take action when you see symptoms of heat exhaustion and 
heat stroke.

To reduce risk during outdoor work, the Occupational Safety and 
Health Administration recommends scheduling frequent rest breaks in 
shaded or air conditioned environments. Anyone overcome by heat 
should be moved to a cool and shaded location. Heat stroke is an 
emergency! Call 9 1 1.

&&

$$

NJZ014-026-310000-
/O.CON.KPHI.HT.Y.0009.000000T0000Z-250731T0000Z/
Eastern Monmouth-Coastal Ocean-
Including the cities of Sandy Hook and Long Beach Island
211 PM EDT Wed Jul 30 2025

...HEAT ADVISORY REMAINS IN EFFECT UNTIL 8 PM EDT THIS EVENING...

* WHAT...Heat index values up to 104.

* WHERE...Eastern Monmouth and Coastal Ocean Counties.

* WHEN...Until 8 PM EDT this evening.

* IMPACTS...Hot temperatures and high humidity may cause heat 
  illnesses.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Drink plenty of fluids, stay in an air-conditioned room, stay out of 
the sun, and check up on relatives and neighbors.

Take extra precautions when outside. Wear lightweight and loose 
fitting clothing. Try to limit strenuous activities to early morning 
or evening. Take action when you see symptoms of heat exhaustion and 
heat stroke.

To reduce risk during outdoor work, the Occupational Safety and 
Health Administration recommends scheduling frequent rest breaks in 
shaded or air conditioned environments. Anyone overcome by heat 
should be moved to a cool and shaded location. Heat stroke is an 
emergency! Call 9 1 1.

&&

$$

MPS
022 
WWUS71 KPHI 302355
NPWPHI

URGENT - WEATHER MESSAGE
National Weather Service Mount Holly NJ
755 PM EDT Wed Jul 30 2025

DEZ001-NJZ001-007>010-012>015-017>020-026-027-PAZ054-055-060>062-070-
071-101>106-310100-
/O.EXP.KPHI.HT.Y.0009.000000T0000Z-250731T0000Z/
New Castle-Sussex-Warren-Morris-Hunterdon-Somerset-Middlesex-
Western Monmouth-Eastern Monmouth-Mercer-Gloucester-Camden-
Northwestern Burlington-Ocean-Coastal Ocean-Southeastern
Burlington-Carbon-Monroe-Berks-Lehigh-Northampton-Delaware-
Philadelphia-Western Chester-Eastern Chester-Western Montgomery-
Eastern Montgomery-Upper Bucks-Lower Bucks-
Including the cities of Flemington, Somerville, Oxford, Media,
Bethlehem, Chalfont, Allentown, Trenton, Mount Holly, Long Beach
Island, Sandy Hook, Stroudsburg, Wharton State Forest, Easton,
Kennett Square, Honey Brook, Glassboro, Doylestown, Washington,
Morrisville, Collegeville, Pottstown, Freehold, Reading, Cherry
Hill, Camden, Newton, Jackson, Jim Thorpe, Norristown, Lansdale,
Morristown, Wilmington, Moorestown, Perkasie, New Brunswick,
Philadelphia, and West Chester
755 PM EDT Wed Jul 30 2025

...HEAT ADVISORY WILL EXPIRE AT 8 PM EDT THIS EVENING...

Heat index values remain hot and humid this evening but are slowly 
coming down below heat advisory thresholds. Continue to take extra 
precautions when outside and limit strenuous activities this evening.

$$

Deal

What forecasters said that day

The local office's own words before this heat advisory went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Philadelphia/Mount Holly wrote its last area forecast discussion before this heat advisory went out at Jul 28, 1:44 AM EDT, 1 hour 16 minutes earlier.

Area forecast discussion, Jul 28, 1:44 AM EDT, 1 hour 16 minutes before
Area Forecast Discussion
National Weather Service Mount Holly NJ
144 AM EDT Mon Jul 28 2025

.SYNOPSIS...
High pressure for the early part of the upcoming week. A cold
front arrives during the midweek period. More high pressure
should be across the region for late next week and into next
weekend.

&&

.NEAR TERM /THROUGH TODAY/...
Overnight, conditions look to remain dry in the wake of a front
crossing the region. Some fog will develop overnight with
residual moisture lingering and light winds behind the front.
Not confident of dense fog at the moment, so we'll broad brush
the patchy for in the grids. Humid and muggy overnight with
lows in the 70s. Light West to Northwest winds.

For Monday, the front will have crossed the area and high pressure
from the Ohio Valley will begin to build in. Upper heights will be
increasing too, so fair weather and hot temperatures are expected.
Dew points will still be uncomfortable (in the low 70s) but a little
less than the past few days (when we had mid/upper 70s). For this
reason, heat index values mostly settle in the upper 90s and low
100's for Delmarva. These numbers are just a few degrees short
of Heat Advisory criteria. We'll hold on any heat headlines for
now with the idea being that even lower dew points are possible.
Winds will be North to Northwest during the day at around 10mph.
At the shore, a sea- breeze is expected for the afternoon.

&&

.SHORT TERM /TONIGHT THROUGH WEDNESDAY/...
The short term period as a whole will feature mostly dry conditions
under mostly sunny/partly cloudy skies as broad high pressure builds
into the region from the south. Perhaps a stray shower or storm is
possible on Tuesday, with more in the way of isolated storms and
increasing clouds on Wednesday ahead of a cold front.

The more notable part of the mid-week period will be another round
of potentially dangerous heat and humidity setting up across the
area. High temperatures on both Tuesday and Wednesday are forecast
to be in the mid to upper 90s with dew points in the low to mid 70s
both days. This will result in heat indicies around 100-105+ degrees
across most of the area; where Wednesday now looks to be the warmest
day. Likely will need some sort of heat headlines on Tuesday and
Wednesday in the coming days.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
The most notable change to the long term period is with regards to
the timing of the arrival of the strong cold front that will be
tracking through the region. Latest guidance further delays this
arrival, with the front now moving into the area late Wednesday
night into Thursday. As stated above, much of the day Wednesday now
looks quite dry, with increasing chances for showers and storms
beginning Wednesday night and continuing through Thursday. Still,
much of the machine learning guidance hints at the potential for
severe weather for both Wednesday night and Thursday, however the
extent of this is uncertain. If the front moves in at night, this
will likely hinder the extent of severe weather potential compared
to maximizing diurnal heating during the day. Will need to continue
to monitor this trend and potential in the coming days. Regardless,
this does look like the next opportunity to bring some widespread
rain and storms to the area. Also, PWATs are expected to be in
excess of 2", which may exacerbate the flash flood risk especially
if any training occurs. Due to this, WPC has portions of the region
in a MARGINAL risk of excessive rainfall on Wednesday with a
MARGINAL and SLIGHT risk of excessive rainfall on Thursday.

By Friday, depending on the forward progression of the front, there
will likely be some lingering shower activity around through Friday,
especially across the Delmarva. Fortunately, by the time the weekend
rolls around, we should see some drastic improvements across the
area with strong high pressure building over the Great Lakes. This
will result in dry conditions with temperatures expected to be as
much as 5-10 degrees below average over the weekend.

&&

.AVIATION /06Z MONDAY THROUGH FRIDAY/...
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY and surrounding areas.

Tonight...Mainly VFR. Mist/patchy fog expected overnight with
some MVFR vsbys forecast in the terminals. Lower conditions
possible but high uncertainty. Low confidence.

Monday... Early morning mist/fog then VFR with sunny skies
expected. North winds 5 to 10 knots becoming West during the
afternoon. High confid.

Outlook...

Monday night through Wednesday...VFR. No significant weather
expected.

Wednesday night through Friday...Sub-VFR conditions probable with
showers likely. A chance for showers and thunderstorms possible in
each afternoon and evening.

&&

.MARINE...
Overnight, winds continue to veer as a front crosses
the waters. By Monday morning, winds will be more North or
Northeast. Speeds will be around 10 to 15 knots on the ocean
into the evening then less than 10 knots overnight and much of
Monday. Sub-SCA expected.

Outlook...

Monday night through Thursday...No marine headlines expected. Winds
will largely remain below 20 kt with seas around 2 feet or less.
Fair weather expected through Wednesday with showers and
thunderstorms for Wednesday night into Thursday.

Thursday night through Friday...SCA conditions probable due to winds
around 25 kt and seas building to 3-5 feet. Showers and
thunderstorms possible.

Rip Currents...

For Monday, winds start northerly and then turn easterly around
5 to 10 MPH. Breakers will be around 1 foot. Period will be 4
to 8 seconds. As a result, a LOW risk for rip currents is in
place at all beaches.

For Tuesday, winds turn southwesterly around 5 to 10 MPH.
Breakers will remain around 1 foot. Period will remain 4 to 8
seconds. As a result, a LOW risk for rip currents is in place at
all beaches.

For specific beach forecasts, visit weather.gov/beach/phi

&&

.CLIMATE...
Several days of high heat will commence Monday and continue
through Wednesday. Here's a rundown of record warm high and
low temperatures.

Record warm high temperatures
Site                Monday 7/28  Tuesday 7/29  Wednesday 7/30
AC Marina (55N)      96 in 1999   96 in 2002    99 in 2002
AC Airport (ACY)     98 in 1999   98 in 2002    96 in 2002
Allentown (ABE)      97 in 1949   96 in 1954    97 in 1940
Georgetown (GED)     99 in 1949   99 in 2011    99 in 1949
Mount Pocono (MPO)   93 in 1949   90 in 1949    90 in 1954
Philadelphia (PHL)  100 in 1941   98 in 2002    98 in 1988
Reading (RDG)        99 in 1941   97 in 2002    97 in 1940
Trenton (TTN)        98 in 1940  100 in 1894    98 in 1999
Wilmington (ILG)    101 in 1894   99 in 1896    97 in 1954

Record warm low temperatures
Site                Monday 7/28  Tuesday 7/29  Wednesday 7/30
AC Marina (55N)      78 in 2020   78 in 2020    79 in 2020
AC Airport (ACY)     80 in 2020   78 in 2002    76 in 2015
Allentown (ABE)      75 in 1934   75 in 2002    74 in 2024
Georgetown (GED)     76 in 2022   78 in 2011    78 in 2009
Mount Pocono (MPO)   69 in 1955   71 in 2002    68 in 1909
Philadelphia (PHL)   79 in 2020   81 in 1995    80 in 2002
Reading (RDG)        78 in 1949   78 in 1949    75 in 1933
Trenton (TTN)        78 in 1894   80 in 1894    78 in 1894
Wilmington (ILG)     76 in 2020   82 in 1894    75 in 2019

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...None.
NJ...None.
DE...None.
MD...None.
MARINE...None.

&&

SYNOPSIS...DeSilva/OHara
NEAR TERM...AKL/OHara
SHORT TERM...DeSilva
LONG TERM...DeSilva
AVIATION...AKL/DeSilva/OHara/RCM
MARINE...AKL/DeSilva/OHara/RCM/Robertson
CLIMATE...WFO PHI
Hazardous weather outlook, Jul 27, 3:44 PM EDT, 11 hours 16 minutes before
Hazardous Weather Outlook
National Weather Service Mount Holly NJ
344 PM EDT Sun Jul 27 2025

MDZ012-015-019-020-281945-
Kent MD-Queen Annes-Talbot-Caroline-
344 PM EDT Sun Jul 27 2025

This Hazardous Weather Outlook is for northeast Maryland.

.DAY ONE...This afternoon and tonight.

No hazardous weather is expected at this time.

.DAYS TWO THROUGH SEVEN...Monday through Saturday.

Heat index values over 100 will be possible for Tuesday and
Wednesday.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not expected at this time.

Nearby

Heat Advisories in New Jersey, 2025Heat Advisories in Pennsylvania, 2025Heat Advisories in Delaware, 2025Every heat advisory in 2025

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.