Alert archive / New Jersey / Heat Advisories in 2025

Heat Advisory 6, NWS Philadelphia/Mount Holly

July 16, 20254 states

NWS Philadelphia/Mount Holly issued this heat advisory at Jul 16, 2025, 1:55 AM EDT for 4 states. It took effect at Jul 17, 2025, 10:00 AM EDT. It was in force for 10 hr.

The area

The counties it named.

The facts

Issued
Jul 16, 2025, 1:55 AM EDT (05:55 UTC)
In effect from
Jul 17, 2025, 10:00 AM EDT
Expired
Jul 17, 2025, 8:00 PM EDT
In force
10 hr
Issued by
NWS Philadelphia/Mount Holly
All 31 counties

Kent County, DE, New Castle County, DE, Sussex County, DE, Caroline County, MD, Kent County, MD, Queen Anne's County, MD, Talbot County, MD, Atlantic County, NJ, Burlington County, NJ, Camden County, NJ, Cape May County, NJ, Cumberland County, NJ, Gloucester County, NJ, Hunterdon County, NJ, Mercer County, NJ, Middlesex County, NJ, Monmouth County, NJ, Morris County, NJ, Ocean County, NJ, Salem County, NJ, Somerset County, NJ, Sussex County, NJ, Warren County, NJ, Berks County, PA, Bucks County, PA, Chester County, PA, Delaware County, PA, Lehigh County, PA, Montgomery County, PA, Northampton County, PA, Philadelphia County, PA

The radar

The Philadelphia radar (KDIX), 65 km from the middle of the area, began a volume at 05:56 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

Washington/Dulle, VA (KIAD), launched 00:00Z, 5.9 hours before the alert went out and 219 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, Washington/Dulle, VA at 00:00Z on 2025-07-16Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1378 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, Washington/Dulle, VA at 00:00Z on 2025-07-16The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -9 square meters per square second.1939Sfc1 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
1378 J/kg
Mixed-layer CIN
-4 J/kg
Mixed-layer LCL
1209 m above ground
0-6 km bulk shear
9 kt
0-1 km storm-relative helicity
-9 m²/s²
0-3 km storm-relative helicity
-18 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

404 
WWUS71 KPHI 160555
NPWPHI

URGENT - WEATHER MESSAGE
National Weather Service Mount Holly NJ
155 AM EDT Wed Jul 16 2025

DEZ001-NJZ012>015-017>020-026-027-PAZ070-071-104-106-162100-
/O.NEW.KPHI.HT.Y.0006.250717T1400Z-250718T0000Z/
New Castle-Middlesex-Western Monmouth-Eastern Monmouth-Mercer-
Gloucester-Camden-Northwestern Burlington-Ocean-Coastal Ocean-
Southeastern Burlington-Delaware-Philadelphia-Eastern Montgomery-
Lower Bucks-
Including the cities of Wilmington, Sandy Hook, Philadelphia, New
Brunswick, Jackson, Mount Holly, Morrisville, Norristown,
Lansdale, Doylestown, Media, Cherry Hill, Long Beach Island,
Glassboro, Freehold, Camden, Moorestown, Wharton State Forest,
and Trenton
155 AM EDT Wed Jul 16 2025

...HEAT ADVISORY IN EFFECT FROM 10 AM TO 8 PM EDT THURSDAY...

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

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

* WHEN...From 10 AM to 8 PM EDT Thursday.

* 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.

&&

$$

DEZ002>004-MDZ012-015-019-020-NJZ016-021>025-162100-
/O.NEW.KPHI.HT.Y.0006.250717T1400Z-250718T0000Z/
Kent-Inland Sussex-Delaware Beaches-Kent MD-Queen Annes-Talbot-
Caroline-Salem-Cumberland-Atlantic-Cape May-Atlantic Coastal Cape
May-Coastal Atlantic-
Including the cities of Georgetown, Rehoboth Beach, Centreville,
Easton, Dover, Pennsville, Hammonton, Atlantic City, Chestertown,
Cape May Court House, Denton, Millville, and Ocean City
155 AM EDT Wed Jul 16 2025

...HEAT ADVISORY IN EFFECT FROM 10 AM TO 8 PM EDT THURSDAY...

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

* WHERE...Portions of central and southern Delaware, northeast 
  Maryland, and southern New Jersey.

* WHEN...From 10 AM to 8 PM EDT Thursday.

* 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>010-PAZ060>062-101>103-105-162100-
/O.NEW.KPHI.HT.Y.0006.250717T1400Z-250718T0000Z/
Sussex-Warren-Morris-Hunterdon-Somerset-Berks-Lehigh-Northampton-
Western Chester-Eastern Chester-Western Montgomery-Upper Bucks-
Including the cities of Somerville, Oxford, Collegeville,
Flemington, Newton, Washington, Easton, Pottstown, Morristown,
Bethlehem, Perkasie, Allentown, Honey Brook, West Chester,
Reading, Kennett Square, and Chalfont
155 AM EDT Wed Jul 16 2025

...HEAT ADVISORY IN EFFECT FROM 10 AM TO 8 PM EDT THURSDAY...

* WHAT...Heat index values up to 100 degrees expected.

* WHERE...Portions of northern and northwest New Jersey and east 
  central and southeast Pennsylvania.

* WHEN...From 10 AM to 8 PM EDT Thursday.

* 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
4 follow-up statements
414 
WWUS71 KPHI 162012
NPWPHI

URGENT - WEATHER MESSAGE
National Weather Service Mount Holly NJ
412 PM EDT Wed Jul 16 2025

DEZ001-NJZ012>015-017>020-026-027-PAZ070-071-104-106-170915-
/O.CON.KPHI.HT.Y.0006.250717T1400Z-250718T0000Z/
New Castle-Middlesex-Western Monmouth-Eastern Monmouth-Mercer-
Gloucester-Camden-Northwestern Burlington-Ocean-Coastal Ocean-
Southeastern Burlington-Delaware-Philadelphia-Eastern Montgomery-
Lower Bucks-
Including the cities of Jackson, Philadelphia, Wilmington, Mount
Holly, Norristown, Wharton State Forest, Lansdale, Cherry Hill,
Long Beach Island, Morrisville, Trenton, Moorestown, Freehold,
New Brunswick, Sandy Hook, Doylestown, Camden, Media, and
Glassboro
412 PM EDT Wed Jul 16 2025

...HEAT ADVISORY REMAINS IN EFFECT FROM 10 AM TO 8 PM EDT THURSDAY...

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

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

* WHEN...From 10 AM to 8 PM EDT Thursday.

* 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.

&&

$$

DEZ002>004-MDZ012-015-019-020-NJZ016-021>025-170915-
/O.CON.KPHI.HT.Y.0006.250717T1400Z-250718T0000Z/
Kent-Inland Sussex-Delaware Beaches-Kent MD-Queen Annes-Talbot-
Caroline-Salem-Cumberland-Atlantic-Cape May-Atlantic Coastal Cape
May-Coastal Atlantic-
Including the cities of Centreville, Georgetown, Easton, Atlantic
City, Denton, Dover, Millville, Chestertown, Hammonton, Ocean
City, Pennsville, Cape May Court House, and Rehoboth Beach
412 PM EDT Wed Jul 16 2025

...HEAT ADVISORY REMAINS IN EFFECT FROM 10 AM TO 8 PM EDT THURSDAY...

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

* WHERE...Portions of central and southern Delaware, northeast 
  Maryland, and southern New Jersey.

* WHEN...From 10 AM to 8 PM EDT Thursday.

* 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>010-PAZ060>062-101>103-105-170915-
/O.CON.KPHI.HT.Y.0006.250717T1400Z-250718T0000Z/
Sussex-Warren-Morris-Hunterdon-Somerset-Berks-Lehigh-Northampton-
Western Chester-Eastern Chester-Western Montgomery-Upper Bucks-
Including the cities of Honey Brook, Easton, Collegeville,
Morristown, Somerville, Washington, Bethlehem, Chalfont, Newton,
Allentown, Oxford, West Chester, Kennett Square, Pottstown,
Perkasie, Flemington, and Reading
412 PM EDT Wed Jul 16 2025

...HEAT ADVISORY REMAINS IN EFFECT FROM 10 AM TO 8 PM EDT THURSDAY...

* WHAT...Heat index values up to 100 expected.

* WHERE...Portions of northern and northwest New Jersey and east 
  central and southeast Pennsylvania.

* WHEN...From 10 AM to 8 PM EDT Thursday.

* 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.

&&

$$

Hoeflich
595 
WWUS71 KPHI 170651
NPWPHI

URGENT - WEATHER MESSAGE
National Weather Service Mount Holly NJ
251 AM EDT Thu Jul 17 2025

DEZ001-NJZ012>015-017>020-026-027-PAZ070-071-104-106-172100-
/O.CON.KPHI.HT.Y.0006.250717T1400Z-250718T0000Z/
New Castle-Middlesex-Western Monmouth-Eastern Monmouth-Mercer-
Gloucester-Camden-Northwestern Burlington-Ocean-Coastal Ocean-
Southeastern Burlington-Delaware-Philadelphia-Eastern Montgomery-
Lower Bucks-
Including the cities of Glassboro, Cherry Hill, Long Beach
Island, New Brunswick, Lansdale, Media, Moorestown, Sandy Hook,
Freehold, Wharton State Forest, Jackson, Trenton, Mount Holly,
Doylestown, Camden, Philadelphia, Norristown, Wilmington, and
Morrisville
251 AM EDT Thu Jul 17 2025

...HEAT ADVISORY REMAINS IN EFFECT FROM 10 AM THIS MORNING TO 8 PM 
EDT THIS EVENING...

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

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

* WHEN...From 10 AM this morning to 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.

&&

$$

DEZ002>004-MDZ012-015-019-020-NJZ016-021>025-172100-
/O.CON.KPHI.HT.Y.0006.250717T1400Z-250718T0000Z/
Kent-Inland Sussex-Delaware Beaches-Kent MD-Queen Annes-Talbot-
Caroline-Salem-Cumberland-Atlantic-Cape May-Atlantic Coastal Cape
May-Coastal Atlantic-
Including the cities of Hammonton, Centreville, Ocean City,
Chestertown, Georgetown, Cape May Court House, Dover, Atlantic
City, Rehoboth Beach, Pennsville, Denton, Millville, and Easton
251 AM EDT Thu Jul 17 2025

...HEAT ADVISORY REMAINS IN EFFECT FROM 10 AM THIS MORNING TO 8 PM 
EDT THIS EVENING...

* WHAT...Heat index values up to 106 degrees expected.

* WHERE...Portions of central and southern Delaware, northeast 
  Maryland, and southern New Jersey.

* WHEN...From 10 AM this morning to 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>010-PAZ060>062-101>103-105-172100-
/O.CON.KPHI.HT.Y.0006.250717T1400Z-250718T0000Z/
Sussex-Warren-Morris-Hunterdon-Somerset-Berks-Lehigh-Northampton-
Western Chester-Eastern Chester-Western Montgomery-Upper Bucks-
Including the cities of Chalfont, Washington, Morristown,
Perkasie, Honey Brook, Pottstown, Bethlehem, Flemington,
Allentown, Somerville, Reading, West Chester, Newton,
Collegeville, Oxford, Kennett Square, and Easton
251 AM EDT Thu Jul 17 2025

...HEAT ADVISORY REMAINS IN EFFECT FROM 10 AM THIS MORNING TO 8 PM 
EDT THIS EVENING...

* WHAT...Heat index values up to 101 degrees expected.

* WHERE...Portions of northern and northwest New Jersey and east 
  central and southeast Pennsylvania.

* WHEN...From 10 AM this morning to 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.

&&

$$

DeSilva
471 
WWUS71 KPHI 171932
NPWPHI

URGENT - WEATHER MESSAGE
National Weather Service Mount Holly NJ
332 PM EDT Thu Jul 17 2025

DEZ001-NJZ012>015-017>020-026-027-PAZ070-071-104-106-180000-
/O.CON.KPHI.HT.Y.0006.000000T0000Z-250718T0000Z/
New Castle-Middlesex-Western Monmouth-Eastern Monmouth-Mercer-
Gloucester-Camden-Northwestern Burlington-Ocean-Coastal Ocean-
Southeastern Burlington-Delaware-Philadelphia-Eastern Montgomery-
Lower Bucks-
Including the cities of Norristown, Freehold, Jackson, Trenton,
Cherry Hill, Doylestown, Wilmington, Philadelphia, Mount Holly,
Media, Moorestown, New Brunswick, Morrisville, Long Beach Island,
Wharton State Forest, Sandy Hook, Lansdale, Glassboro, and Camden
332 PM EDT Thu Jul 17 2025

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

* WHAT...Heat index values up to 101.

* WHERE...Portions of northern Delaware, central, northern, 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.

&&

$$

DEZ002>004-MDZ012-015-019-020-NJZ016-021>025-180000-
/O.CON.KPHI.HT.Y.0006.000000T0000Z-250718T0000Z/
Kent-Inland Sussex-Delaware Beaches-Kent MD-Queen Annes-Talbot-
Caroline-Salem-Cumberland-Atlantic-Cape May-Atlantic Coastal Cape
May-Coastal Atlantic-
Including the cities of Millville, Dover, Cape May Court House,
Easton, Ocean City, Hammonton, Rehoboth Beach, Atlantic City,
Denton, Centreville, Pennsville, Chestertown, and Georgetown
332 PM EDT Thu Jul 17 2025

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

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

* WHERE...Portions of central and southern Delaware, northeast 
  Maryland, and southern New Jersey.

* 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>010-PAZ060>062-101>103-105-180000-
/O.CON.KPHI.HT.Y.0006.000000T0000Z-250718T0000Z/
Sussex-Warren-Morris-Hunterdon-Somerset-Berks-Lehigh-Northampton-
Western Chester-Eastern Chester-Western Montgomery-Upper Bucks-
Including the cities of Reading, West Chester, Allentown, Newton,
Chalfont, Easton, Honey Brook, Kennett Square, Washington,
Pottstown, Perkasie, Morristown, Oxford, Collegeville,
Flemington, Somerville, and Bethlehem
332 PM EDT Thu Jul 17 2025

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

* WHAT...Heat index values up to 101.

* WHERE...Portions of northern and northwest New Jersey and east 
  central 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.

&&

$$

Hoeflich
145 
WWUS71 KPHI 180001
NPWPHI

URGENT - WEATHER MESSAGE
National Weather Service Mount Holly NJ
801 PM EDT Thu Jul 17 2025

DEZ001>004-MDZ012-015-019-020-NJZ001-007>010-012>027-PAZ060>062-070-
071-101>106-180115-
/O.EXP.KPHI.HT.Y.0006.000000T0000Z-250718T0000Z/
New Castle-Kent-Inland Sussex-Delaware Beaches-Kent MD-Queen
Annes-Talbot-Caroline-Sussex-Warren-Morris-Hunterdon-Somerset-
Middlesex-Western Monmouth-Eastern Monmouth-Mercer-Salem-
Gloucester-Camden-Northwestern Burlington-Ocean-Cumberland-
Atlantic-Cape May-Atlantic Coastal Cape May-Coastal Atlantic-
Coastal Ocean-Southeastern Burlington-Berks-Lehigh-Northampton-
Delaware-Philadelphia-Western Chester-Eastern Chester-Western
Montgomery-Eastern Montgomery-Upper Bucks-Lower Bucks-
Including the cities of Easton, Long Beach Island, Chalfont,
Somerville, Millville, Moorestown, Rehoboth Beach, Oxford,
Perkasie, Doylestown, Jackson, Sandy Hook, Newton, Kennett
Square, Wharton State Forest, Bethlehem, Norristown, New
Brunswick, Honey Brook, Trenton, Dover, Freehold, Washington,
Georgetown, Glassboro, Flemington, Pennsville, Media, Hammonton,
Ocean City, Reading, Collegeville, Denton, Chestertown,
Allentown, Morristown, Wilmington, Lansdale, Mount Holly, Cape
May Court House, Atlantic City, Pottstown, Philadelphia,
Morrisville, Camden, Centreville, West Chester, and Cherry Hill
801 PM EDT Thu Jul 17 2025

...HEAT ADVISORY HAS EXPIRED...

The threat has ended as temperatures are dropping below Heat 
Advisory thresholds.

$$

Fitzsimmons

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 16, 1:24 AM EDT, 31 minutes earlier.

Area forecast discussion, Jul 16, 1:24 AM EDT, 31 minutes before
Area Forecast Discussion
National Weather Service Mount Holly NJ
124 AM EDT Wed Jul 16 2025

.SYNOPSIS...
A very warm and humid airmass will be over the region this week with
multiple rounds of showers and thunderstorms expected. A cold front
remains stalled within the vicinity of the area today before
lifting back northward as a warm front on Thursday. A cold front
passes through the region on Friday with high pressure building
in on Saturday. Another cold front approaches late in the
weekend, lingering through the early part of the week.

&&

.NEAR TERM /THROUGH TODAY/...
A weak boundary continues to sit over Delmarva into southern NJ and
this boundary along with daytime heating and sea/bay breezes is
helping to trigger some scattered convection over portions of
southern DE into coastal NJ. The threat for severe weather with any
of these storms is low but there is a risk of localized flash
flooding as PWATS remain very high (around 2 inches) and storms are
slow moving. The limiting factors for today though are that the
forcing is very weak and there is a mid level dry air...especially
as you head farther north towards the I-95 corridor and points
northward. For this reason, storms will will continue to be isolated
to scattered and be confined primarily to our southern zones.
Farther north it will continue to be warm and humid with a mix of
sun and clouds.

Wednesday will start dry but as we get into the afternoon there will
be some shortwave energy approaching from the west and this will
help trigger another round of convection which is expected to be
more widespread than today. Unlike today, the highest chances for
showers/storms look to be focused near and north of the urban
corridor where we have POPs of 60 to 70 percent. Unfortunately, this
includes the areas that were hard hit yesterday. Model guidance
isn't especially robust depicting widespread heavy QPF amounts but
given the set up of continuing high PWATS (over 2 inches) with
better forcing compared to today and a setup that will favor
training and back building storms we went ahead an issued a Flood
Watch for flash flooding for our counties in central and northern
NJ...this includes from Mercer and Middlesex Counties northward.
These areas are currently very susceptible to more flooding
given yesterday's heavy rain and flash flooding. Within this
area 1 hour FFG is below an inch in places with 3 hour FFG below
2 inches. So it won't take much for these thresholds to be
reached. The severe weather threat for Wednesday continues to
look relatively low however the Storm Prediction Center does now
include portions of our western counties (Berks County
northward through the Lehigh Valley into Carbon County) in a
MARGINAL risk for severe weather. The main threat is damaging
winds. Highs Wednesday look to be mainly in the mid to upper 80s
with dew points in the 70s so it will be quite muggy with heat
indices topping out in the middle to high 90s.

Getting into Wednesday night, since the best forcing won't be
arriving until later in the day Wednesday into the evening, the
convection may continue to be relatively widespread through  much of
the evening before diminishing later at night. For this reason, we
ran the Flood Watch to 3 AM Thursday. However the threat for severe
weather will have diminished by the late evening. It will be another
warm and muggy night with lows mostly in the 70s (60s over the
Pocono Plateau).

&&

.SHORT TERM /TONIGHT THROUGH FRIDAY/...
On Thursday, southwesterly flow will bring back warm air and
moisture advection resulting in heat index values approaching 100
degrees in many areas. This is anticipated to be the warmest day of
the week (unless the cold front on Friday is later than currently
expected). A Heat Advisory will need to be considered for Thursday
across portions of the area in a future update. There will again be
chances of diurnally driven showers and thunderstorms on Thursday,
again focused mainly northwest of I-95. Synoptic forcing is again
not very strong, and deep layer shear will be weak. A lot of
uncertainty regarding the convective environment for Thursday, and
we currently have no threats outlooks by WPC or SPC but this could
change especially on the hydrology side of things given how wet it
has been within the area of highest PoPs. PoPs are mostly 40-80%,
with the highest probabilities north and west of Philadelphia.

Thursday night will be the warmest night of the week, with low
temperatures mainly in the mid to upper 70s and should be mainly dry.

Friday could be another hot day depending on the timing of the next
cold front. Latest guidance shows the front crossing through the
region late in the day, and into the overnight hours on Friday. If
that timing holds, most of the area (aside from Delmarva) may be a
degree or two lower on Friday as compared to Thursday. This front
may also act as a focusing mechanism for thunderstorms and
associated convective hazards, but as with Thursday, uncertainty is
high regarding any of these threats. PoPs are near 20-50% for much
of the area.

&&

.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
Heading into the weekend, Saturday should experience the lowest
chance of convection with a surge of slightly drier air, lower
instability, and some subsidence from the departing trough.
Temperatures returning back closer to normal, and a comparatively
nice Saturday looks to be shaping up with highs in the mid 80s and
lower humidity compared to this week. Chances for convection should
increase again some for Sunday as the boundary start lifting north
with return flow.

Unsettled conditions look to hang around through the start of next
week with the boundary lingering over the area, though too early to
say if any impactful severe weather or flood threat will come into
play. Temperatures to start next week look to be near seasonal
norms.

&&

.AVIATION /05Z WEDNESDAY THROUGH SUNDAY/...
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY and surrounding areas.

Through 12Z...Primarily VFR conditions expected. Light and
variable winds, becoming calm at times. A SCT/BKN low cloud deck
may develop after 06Z, so have included TEMPO groups of
MVFR/IFR ceilings possible through 12Z. Confidence in occurrence
is low, but best chance will be across the I-95 corridor and
points north. Low confidence.

Wednesday...Primarily VFR expected outside of lingering low
clouds early. Scattered Showers and isolated thunderstorms
expected to develop in the afternoon, so have maintained VCSH at
all terminals. South-southwest winds around 5-10 kt with
occasional gusts up to 15 kt. Moderate confidence.

Wednesday night...Primarily VFR expected. Scattered showers and
thunderstorms become more widespread into the evening hours, so
have included PROB30 groups at all terminals between 00Z-06Z
from west to east. Localized sub-VFR conditions possible in
heavy showers/storms. South-southwest winds around 5 kt or
less. Low confidence.

Outlook...

Thursday...Primarily VFR, though MVFR/IFR conditions possible (20-
40%) as some showers and thunderstorms develop in the afternoon,
with the highest probability for restrictions coming for KABE/KRDG.

Thursday Night...VFR. No significant weather.

Friday...Primarily VFR, though restrictions possible (15-30%) with
scattered showers and thunderstorms around in the afternoon.

Friday Night...VFR. No significant weather.

Saturday through Saturday Night...Primarily VFR. Isolated showers
around in the afternoon and early evening.

Sunday...Primarily VFR but restrictions possible (40-50%) with
showers and thunderstorms developing in the afternoon.

&&

.MARINE...
No marine headlines are in effect through tonight as SW winds
will be around 10 knots through this period. Scattered showers
and thunderstorms possible through tonight, which may cause
locally gusty winds in excess of 34 kt.

Late day Wednesday into Wednesday night southwest winds increase
to around 15 to 20 with gusts of 20 to 25 knots possible. So a
Small Craft Advisory may be needed though it will be marginal.

Outlook...

Thursday...Sub-SCA conditions expected, though cannot rule out a few
gusts near 25 kt. 15% chance an SCA is needed. Seas 2 to 4 feet.

Thursday Night through Sunday...No marine headlines expected.
Periods of showers and thunderstorms expected, mainly in the
afternoon and evening most days.

Rip Currents...

On Wednesday, south to southwest winds will increase to around
10 mph, with a few gusts to 20 mph possible. Breaking waves will
generally be 1 to 2 feet with an easterly swell around 8
seconds. There is a LOW risk for the development of dangerous
and life threatening rip currents for the Jersey Shore and for
Delaware Beaches.

On Thursday, southwest winds will once again be around 10 to 15
mph with breaking waves 1 to 2 feet and an easterly swell around
8 seconds. This results in a LOW risk for the development of
dangerous and life threatening rip currents for the Jersey Shore
and for Delaware Beaches.

Rip currents occur often in the vicinities of jetties and piers
and the speed of the currents are generally maximized at low
tides.

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

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...None.
NJ...Flood Watch from this afternoon through late tonight for
     NJZ001-007>010-012-015.
DE...None.
MD...None.
MARINE...None.

&&

SYNOPSIS...DeSilva/Hoeflich
NEAR TERM...DeSilva/Fitzsimmons
SHORT TERM...Hoeflich/Johnson/Staarmann
LONG TERM...Hoeflich/Johnson/Staarmann
AVIATION...DeSilva/Fitzsimmons/Hoeflich
MARINE...Fitzsimmons/Hoeflich/MPS
Hazardous weather outlook, Jul 15, 6:09 AM EDT, 19 hours 46 minutes before
Hazardous Weather Outlook
National Weather Service Mount Holly NJ
609 AM EDT Tue Jul 15 2025

MDZ012-015-019-020-161015-
Kent MD-Queen Annes-Talbot-Caroline-
609 AM EDT Tue Jul 15 2025

This Hazardous Weather Outlook is for northeast Maryland.

.DAY ONE...Today and tonight.

Scattered showers and thunderstorms are possible this afternoon into
early this evening. Localized flash flooding may be possible this
afternoon.

.DAYS TWO THROUGH SEVEN...Wednesday through Monday.

Additional rounds of showers and thunderstorms are possible each day
through the end of the week which may cause localized instances of
flash flooding.

.SPOTTER INFORMATION STATEMENT...

Weather spotters are encouraged to report significant weather
conditions according to standard operating procedures.

In the hours before

Local storm report, Jul 15, 8:02 PM EDT, 5 hours 53 minutes before
Preliminary Local Storm Report
National Weather Service Mount Holly NJ
802 PM EDT Tue Jul 15 2025

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0754 PM     Rain             2 SSE Farmington        38.84N 75.56W
07/15/2025  M2.81 Inch       Kent               DE   Public

            2.81 in around 2 hours.

&&

MPS
Local storm report, Jul 15, 11:17 PM EDT, 2 hours 38 minutes before
Preliminary Local Storm Report
National Weather Service Mount Holly NJ
1117 PM EDT Tue Jul 15 2025

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0645 AM     Rain             Watchung                40.64N 74.45W
07/15/2025  M6.41 Inch       Somerset           NJ   Trained Spotter

            Rainfall from Monday.

&&

Staarmann
Local storm report, Jul 15, 11:37 PM EDT, 2 hours 18 minutes before
Preliminary Local Storm Report
National Weather Service Mount Holly NJ
1137 PM EDT Tue Jul 15 2025

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0800 AM     Rain             1 SW Green Brook Twp    40.59N 74.48W
07/15/2025  M6.31 Inch       Somerset           NJ   Cocorahs

            Updates previous rain report from 1 SW Green
            Brook Twp. Rain started around 530 pm. Heavy
            rain lasted several hours. Measured 6.29 at
            945pm, the remaining 0.02 fell shortly
            after. Many roads in Green Brook, Dunellen
            and Middlesex Boro flooded in the evening
            and still remained flooded this morning.

&&

Staarmann

The office that day

Everything else NWS Philadelphia/Mount Holly issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 16, 7:38 PM EDTFlash Flood WarningPHIBucks4 hr
Jul 16, 6:46 PM EDTFlash Flood WarningPHIMiddlesex, Somerset4 hr
Jul 16, 7:31 PM EDTSevere Thunderstorm WarningPHIMonmouth, Ocean29 min
Jul 16, 7:37 PM EDTSpecial Marine WarningPHI38 min
Jul 16, 7:54 PM EDTSevere Thunderstorm WarningPHIMiddlesex, Monmouth, Ocean26 min

Nearby

Heat Advisories in New Jersey, 2025Heat Advisories in Pennsylvania, 2025Heat Advisories in Maryland, 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.