Arizona, 2019

Excessive Heat in Arizona, August 20 to 21, 2019

August 20 to 21, 2019 · NWS TWC · 7 events in 7 counties and zones

Very hot temperatures were recorded in southeast Arizona from Safford and the Tucson Metro westward on August 20th and 21st. Several new high temperature records were established.

Where it happened

Every event with a place to put it; 7 filed by county or forecast zone are drawn at its center, in a lighter ring. Tap one for its entry below.

  • Tornadoes
  • Tropical storms and surge
  • Floods
  • Wind
  • Hail
  • Winter weather
  • Heat and drought
  • Cold
  • Fire, smoke and dust
  • Marine and coastal
  • Other

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The toll

Deaths
2
Injuries
0
Property damage
None recorded
Crop damage
None recorded
Events
7

Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.

What happened

The episode as NWS TWC wrote it up.

Very hot temperatures were recorded in southeast Arizona from Safford and the Tucson Metro westward on August 20th and 21st. Several new high temperature records were established. Two heat-related fatalities occurred in southern Pima County.

What forecasters said that day

The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Tucson, AZ wrote its last area forecast discussion before the first event at Aug 20, 9:00 AM MST, 2 hours earlier.

Area forecast discussion, Aug 20, 9:00 AM MST, 2 hours before
Area Forecast Discussion
National Weather Service Tucson AZ
900 AM MST Tue Aug 20 2019

.SYNOPSIS...Hot, near or above record temperatures are expected
today and Wednesday with dry conditions through early Wednesday.
Increasing moisture late Wednesday onward will bring scattered
thunderstorms to the area with cooler, near normal temperatures this
weekend.

&&

.DISCUSSION...Very hot for August with record to near record high
temperatures on tap for today and tomorrow. Excessive Heat Warning
goes into effect at 11 am for the lower elevations of Pima, Pinal
and Graham counties and continues through 8 pm Wednesday. Moisture
limited across the area today with values mostly less than 1". The
exception is right along the AZ/NM border where values are slightly
above 1". This is where a few storms may develop this afternoon
and also along the Intl border east of Nogales.

Moisture values creep up Wednesday into the 1" to 1.30" range.
This will result in a slight uptick in thunderstorms, but mainly
over the higher terrain south and east of Tucson.

Still looking at an upswing in thunderstorm activity later in the
week. More on this in the afternoon discussion.

&&

.AVIATION...Valid through 21/12Z.
FEW-SCT clouds at 12k-16k ft MSL thru the forecast period. A slight
chance of -TSRA/-SHRA along the International border mainly near
KDUG from about 20/21Z through 21/02Z. SFC wind less than 12 knots
and favoring a NWLY direction in the afternoon/early evening with a
few afternoon gusts to around 15-20 kts. Aviation discussion not
updated for TAF amendments.

&&

.FIRE WEATHER...Limited moisture today will result in any
shower/thunderstorm development remaining confined to areas along
the International Border from Nogales eastward and in the White
Mountains. Near record high temperatures are expected through
Wednesday. A return to more typical monsoonal moisture is expected
to arrive in the area starting Wednesday afternoon and continuing
into the weekend. Thunderstorm coverage initially will be east of
Tucson, then increasing and shifting westward later in the week.
Thunderstorms that do develop may produce gusty and erratic outflow
winds. Otherwise, 20-ft winds will generally follow normal diurnal
trends at less than 15 mph.

&&

.CLIMATE...Record to near record highs today and tomorrow across
southeast Arizona. Below are the forecast highs for today and
Wednesday versus the daily record highs for selection locations
across southeast Arizona.

DATE                         Aug 20           Aug 21
                          FCST RCD/YR      FCST RCD/YR
Tucson Intl Airport       109 110/1915     109 108/1930
Bisbee-Douglas Airport    101 102/2009      98  98/2011
Ajo                       111 113/1915     111 115/1915
Kitt Peak                  90  85/2010      91  86/2010
Organ Pipe Cactus N.M.    112 109/2010     111 112/1969
Picacho Peak              108 107/2007     109 108/1999
Safford Ag Station        107 104/1973     105 105/1986
Sierra Vista               99  98/1911      97  97/2013
Tombstone                 100 103/1917      98 101/1938
Willcox                   102 103/1915     100 105/2009

&&

.TWC WATCHES/WARNINGS/ADVISORIES...
 Excessive Heat Warning until 8 PM MST Wednesday for AZZ501-502-
  504>506-509.

&&

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The radar

The national radar mosaic for the moment the first event began.

Open the radar archive at this moment

Event by event

7 excessive heat. Local standard time, as filed.

Excessive Heat, Western Pima County

When
August 20, 11:00 AM MST to August 21, 8:00 PM MST
Where
Western Pima County forecast zone
Reported by
County Official
Coordinates
32.097, -111.790 (the zone’s center; the record gives no point)

Very hot temperatures occurred on August 20th and 21st, with respective high temperatures of 111 and 113 degrees at Ajo, 109 and 111 degrees (both records) at Picacho, 111 degrees on both days at Sells, 113 degrees on both days (both were records) at Organ Pipe National Monument, 109 and 110 degrees (both records) at Tucson International Airport, 105 and 107 degrees (both records) at Sasabe, 104 and 103 degrees (both records) at Nogales International Airport, 107 degrees on both days (both were records) at Safford airport, and 109 and 108 degrees in the Gila River Valley on the San Carlos Apache Tribe reservation. The Pima County Medical Examiner confirmed that heat was the primary cause of death for one adult male north of Arivaca on the 21st.

Excessive Heat, Tohono O Odham Nation

When
August 20, 11:00 AM MST to August 21, 8:00 PM MST
Where
Tohono O Odham Nation forecast zone
Reported by
County Official
Coordinates
32.501, -111.567 (the zone’s center; the record gives no point)

Very hot temperatures occurred on August 20th and 21st, with respective high temperatures of 111 and 113 degrees at Ajo, 109 and 111 degrees (both records) at Picacho, 111 degrees on both days at Sells, 113 degrees on both days (both were records) at Organ Pipe National Monument, 109 and 110 degrees (both records) at Tucson International Airport, 105 and 107 degrees (both records) at Sasabe, 104 and 103 degrees (both records) at Nogales International Airport, 107 degrees on both days (both were records) at Safford airport, and 109 and 108 degrees in the Gila River Valley on the San Carlos Apache Tribe reservation. The Pima County Medical Examiner confirmed that heat was the primary cause of death for one adult male north of Arivaca on the 21st.

Excessive Heat, Upper Santa Cruz River and Altar Valleys

When
August 20, 11:00 AM MST to August 21, 8:00 PM MST
Where
Upper Santa Cruz River and Altar Valleys forecast zone
Deaths
2 direct, 0 indirect
Reported by
County Official
Coordinates
31.812, -111.318 (the zone’s center; the record gives no point)

Very hot temperatures occurred on August 20th and 21st, with respective high temperatures of 111 and 113 degrees at Ajo, 109 and 111 degrees (both records) at Picacho, 111 degrees on both days at Sells, 113 degrees on both days (both were records) at Organ Pipe National Monument, 109 and 110 degrees (both records) at Tucson International Airport, 105 and 107 degrees (both records) at Sasabe, 104 and 103 degrees (both records) at Nogales International Airport, 107 degrees on both days (both were records) at Safford airport, and 109 and 108 degrees in the Gila River Valley on the San Carlos Apache Tribe reservation. The Pima County Medical Examiner confirmed that heat was the primary cause of death for two persons north of Arivaca on the 21st.

Excessive Heat, Tucson Metro Area

When
August 20, 11:00 AM MST to August 21, 8:00 PM MST
Where
Tucson Metro Area forecast zone
Reported by
County Official
Coordinates
32.097, -111.790 (the zone’s center; the record gives no point)

Very hot temperatures occurred on August 20th and 21st, with respective high temperatures of 111 and 113 degrees at Ajo, 109 and 111 degrees (both records) at Picacho, 111 degrees on both days at Sells, 113 degrees on both days (both were records) at Organ Pipe National Monument, 109 and 110 degrees (both records) at Tucson International Airport, 105 and 107 degrees (both records) at Sasabe, 104 and 103 degrees (both records) at Nogales International Airport, 107 degrees on both days (both were records) at Safford airport, and 109 and 108 degrees in the Gila River Valley on the San Carlos Apache Tribe reservation. The Pima County Medical Examiner confirmed that heat was the primary cause of death for one adult male north of Arivaca on the 21st.

Excessive Heat, South Central Pinal County

When
August 20, 11:00 AM MST to August 21, 8:00 PM MST
Where
South Central Pinal County forecast zone
Reported by
County Official
Coordinates
32.904, -111.345 (the zone’s center; the record gives no point)

Very hot temperatures occurred on August 20th and 21st, with respective high temperatures of 111 and 113 degrees at Ajo, 109 and 111 degrees (both records) at Picacho, 111 degrees on both days at Sells, 113 degrees on both days (both were records) at Organ Pipe National Monument, 109 and 110 degrees (both records) at Tucson International Airport, 105 and 107 degrees (both records) at Sasabe, 104 and 103 degrees (both records) at Nogales International Airport, 107 degrees on both days (both were records) at Safford airport, and 109 and 108 degrees in the Gila River Valley on the San Carlos Apache Tribe reservation. The Pima County Medical Examiner confirmed that heat was the primary cause of death for one adult male north of Arivaca on the 21st.

Excessive Heat, Southeast Pinal County

When
August 20, 11:00 AM MST to August 21, 8:00 PM MST
Where
Southeast Pinal County forecast zone
Reported by
County Official
Coordinates
32.904, -111.345 (the zone’s center; the record gives no point)

Very hot temperatures occurred on August 20th and 21st, with respective high temperatures of 111 and 113 degrees at Ajo, 109 and 111 degrees (both records) at Picacho, 111 degrees on both days at Sells, 113 degrees on both days (both were records) at Organ Pipe National Monument, 109 and 110 degrees (both records) at Tucson International Airport, 105 and 107 degrees (both records) at Sasabe, 104 and 103 degrees (both records) at Nogales International Airport, 107 degrees on both days (both were records) at Safford airport, and 109 and 108 degrees in the Gila River Valley on the San Carlos Apache Tribe reservation. The Pima County Medical Examiner confirmed that heat was the primary cause of death for one adult male north of Arivaca on the 21st.

Excessive Heat, Upper Gila River and Aravaipa Valleys

When
August 20, 11:00 AM MST to August 21, 8:00 PM MST
Where
Upper Gila River and Aravaipa Valleys forecast zone
Reported by
County Official
Coordinates
33.074, -109.563 (the zone’s center; the record gives no point)

Very hot temperatures occurred on August 20th and 21st, with respective high temperatures of 111 and 113 degrees at Ajo, 109 and 111 degrees (both records) at Picacho, 111 degrees on both days at Sells, 113 degrees on both days (both were records) at Organ Pipe National Monument, 109 and 110 degrees (both records) at Tucson International Airport, 105 and 107 degrees (both records) at Sasabe, 104 and 103 degrees (both records) at Nogales International Airport, 107 degrees on both days (both were records) at Safford airport, and 109 and 108 degrees in the Gila River Valley on the San Carlos Apache Tribe reservation. The Pima County Medical Examiner confirmed that heat was the primary cause of death for one adult male north of Arivaca on the 21st.

The people who died

As the offices recorded each death: direct deaths were caused by the weather itself, indirect ones by something it set in motion.

EventDateAgeSexWhereKind
Excessive Heat, Upper Santa Cruz River and Altar Valleys2019-08-2132MaleOutside/Open AreasDirect
Excessive Heat, Upper Santa Cruz River and Altar Valleys2019-08-2121MaleOutside/Open AreasDirect

What these are

Excessive Heat
Heat at or above the local excessive heat warning criteria, or heat that caused deaths.

After NWS Directive 10-1605, the rules offices file Storm Data by.

The same day elsewhere

More

Every storm in Arizona in 2019Every state in 2019This day in weather historyWarnings in Arizona, August 2019

Sources

NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 854719, 875342, 875343, 875344, 875345, 875346, 875347.