Arizona, 2021

Excessive Heat and Heat in Arizona, August 25 to 27, 2021

August 25 to 27, 2021 · NWS TWC · 8 events in 8 counties and zones

Very hot temperatures were experienced in the lower elevations of southeast Arizona August 25 through 27, with high temperatures equaling or exceeding established records in a few locations, and approaching record levels in most others. The Pima County Medical Examiner confirmed that heat was the primary cause of death for one male found in the desert.

Where it happened

Every event with a place to put it; 8 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

Open the live radar over this ground

The toll

Deaths
1
Injuries
0
Property damage
None recorded
Crop damage
None recorded
Events
8

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 experienced in the lower elevations of southeast Arizona August 25 through 27, with high temperatures equaling or exceeding established records in a few locations, and approaching record levels in most others. The Pima County Medical Examiner confirmed that heat was the primary cause of death for one male found in the desert.

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 25, 3:15 AM MST, 6 hours 45 minutes earlier.

Area forecast discussion, Aug 25, 3:15 AM MST, 6 hours 45 minutes before
Area Forecast Discussion
National Weather Service Tucson AZ
315 AM MST Wed Aug 25 2021

.SYNOPSIS...High pressure will bring hotter temperatures through at
least Friday before somewhat cooler readings arrive by early next
week. Isolated thunderstorms can be expected each day, before an
increase in coverage commences this weekend into early next week.

&&

.DISCUSSION...Rather limited thunderstorm activity will continue
each afternoon and evening through at least Friday. Recent high
resolution models depicted limited shower and thunderstorm coverage
for today despite deeper moisture inching closer to SE AZ. This
suppressed thunderstorm activity in combination with the westward
expansion of the upper high center over central United States will
result in hotter temperatures starting today. The projected high
temperatures in the lower deserts of Pima, Pinal, and Graham
counties will result in elevated heat related risks today through
Friday. Thereafter, ensembles were still pointing toward a more
favorable environment for an increase in thunderstorm coverage
commencing this weekend and more so early next week. A tropical
system approaching Baja will be the feature to keep an eye on as it
will likely play a significant role in the upcoming rain chances.
Relief in the heat will also coincide with an increase in moisture
and subsequent thunderstorm activity.

&&

.AVIATION...Valid through 26/12Z.
Isolated -SHRA/-TSRA will develop east of KTUS and KOLS this
afternoon and into the evening.  FEW-SCT clouds are expected to
develop at 8k-12k ft agl this afternoon with decreasing coverage
overnight. Winds will favor a northwesterly component this
afternoon, remaining around 10 knots before decreasing this evening.
Expect similar winds tomorrow. Aviation discussion not updated for
TAF amendments.

&&

.FIRE WEATHER...
A near to below normal monsoon pattern is expected through late this
week. Isolated to scattered storms will be possible each afternoon
primarily east and south of Tucson and over the higher elevations.
An upswing in thunderstorm activity will be possible this weekend
into early next week. Temperatures will remain above normal through
at least Friday with triple digit readings expected for much of the
lower deserts. 20-foot winds will generally be less than 15 mph when
not influenced by thunderstorms and RH values are expected to remain
above critical thresholds.

&&

.TWC WATCHES/WARNINGS/ADVISORIES...
   Excessive Heat Warning from 10 AM this morning to 8 PM MST Friday
   for AZZ501-502-504>507-509.

&&

Visit us on Facebook...Twitter...YouTube...and at weather.gov/Tucson

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, 1 heat. Local standard time, as filed.

Excessive Heat, Western Pima County

When
August 25, 10:00 AM MST to August 27, 8:00 PM MST
Where
Western Pima County forecast zone
Reported by
Mesonet
Coordinates
32.097, -111.790 (the zone’s center; the record gives no point)

Very hot high temperatures of 104 to 114 degrees, or 5 to 11 degrees above normal, occurred in the lower elevations of Pima, southeast Pinal, and northwest sections of Cochise and Graham counties August 25-27 and caused the High Heat Risk category to be reached. The highest temperatures at select locations during the period were 114 degrees (tied record on 8/27) at Ajo, 112 (both records on 8/26 and 8/27) at Organ Pipe Cactus National Monument, 111 (record on 8/26) at Sells, 108 (one degree shy of the record on 8/27) at Picacho, 106 on 8/26 at Tucson International Airport, 105 on 8/25 and 8/26 at San Carlos and 103 on 8/25 at Cascabel.

Excessive Heat, Tohono O Odham Nation

When
August 25, 10:00 AM MST to August 27, 8:00 PM MST
Where
Tohono O Odham Nation forecast zone
Reported by
Mesonet
Coordinates
32.501, -111.567 (the zone’s center; the record gives no point)

Very hot high temperatures of 104 to 114 degrees, or 5 to 11 degrees above normal, occurred in the lower elevations of Pima, southeast Pinal, and northwest sections of Cochise and Graham counties August 25-27 and caused the High Heat Risk category to be reached. The highest temperatures at select locations during the period were 114 degrees (tied record on 8/27) at Ajo, 112 (both records on 8/26 and 8/27) at Organ Pipe Cactus National Monument, 111 (record on 8/26) at Sells, 108 (one degree shy of the record on 8/27) at Picacho, 106 on 8/26 at Tucson International Airport, 105 on 8/25 and 8/26 at San Carlos and 103 on 8/25 at Cascabel.

Excessive Heat, Tucson Metro Area

When
August 25, 10:00 AM MST to August 27, 8:00 PM MST
Where
Tucson Metro Area forecast zone
Reported by
Mesonet
Coordinates
32.097, -111.790 (the zone’s center; the record gives no point)

Very hot high temperatures of 104 to 114 degrees, or 5 to 11 degrees above normal, occurred in the lower elevations of Pima, southeast Pinal, and northwest sections of Cochise and Graham counties August 25-27 and caused the High Heat Risk category to be reached. The highest temperatures at select locations during the period were 114 degrees (tied record on 8/27) at Ajo, 112 (both records on 8/26 and 8/27) at Organ Pipe Cactus National Monument, 111 (record on 8/26) at Sells, 108 (one degree shy of the record on 8/27) at Picacho, 106 on 8/26 at Tucson International Airport, 105 on 8/25 and 8/26 at San Carlos and 103 on 8/25 at Cascabel.

Excessive Heat, South Central Pinal County

When
August 25, 10:00 AM MST to August 27, 8:00 PM MST
Where
South Central Pinal County forecast zone
Reported by
Mesonet
Coordinates
32.904, -111.345 (the zone’s center; the record gives no point)

Very hot high temperatures of 104 to 114 degrees, or 5 to 11 degrees above normal, occurred in the lower elevations of Pima, southeast Pinal, and northwest sections of Cochise and Graham counties August 25-27 and caused the High Heat Risk category to be reached. The highest temperatures at select locations during the period were 114 degrees (tied record on 8/27) at Ajo, 112 (both records on 8/26 and 8/27) at Organ Pipe Cactus National Monument, 111 (record on 8/26) at Sells, 108 (one degree shy of the record on 8/27) at Picacho, 106 on 8/26 at Tucson International Airport, 105 on 8/25 and 8/26 at San Carlos and 103 on 8/25 at Cascabel.

Excessive Heat, Southeast Pinal County

When
August 25, 10:00 AM MST to August 27, 8:00 PM MST
Where
Southeast Pinal County forecast zone
Reported by
Mesonet
Coordinates
32.904, -111.345 (the zone’s center; the record gives no point)

Very hot high temperatures of 104 to 114 degrees, or 5 to 11 degrees above normal, occurred in the lower elevations of Pima, southeast Pinal, and northwest sections of Cochise and Graham counties August 25-27 and caused the High Heat Risk category to be reached. The highest temperatures at select locations during the period were 114 degrees (tied record on 8/27) at Ajo, 112 (both records on 8/26 and 8/27) at Organ Pipe Cactus National Monument, 111 (record on 8/26) at Sells, 108 (one degree shy of the record on 8/27) at Picacho, 106 on 8/26 at Tucson International Airport, 105 on 8/25 and 8/26 at San Carlos and 103 on 8/25 at Cascabel.

Excessive Heat, Upper San Pedro River Valley

When
August 25, 10:00 AM MST to August 27, 8:00 PM MST
Where
Upper San Pedro River Valley forecast zone
Reported by
Mesonet
Coordinates
32.109, -110.569 (the zone’s center; the record gives no point)

Very hot high temperatures of 104 to 114 degrees, or 5 to 11 degrees above normal, occurred in the lower elevations of Pima, southeast Pinal, and northwest sections of Cochise and Graham counties August 25-27 and caused the High Heat Risk category to be reached. The highest temperatures at select locations during the period were 114 degrees (tied record on 8/27) at Ajo, 112 (both records on 8/26 and 8/27) at Organ Pipe Cactus National Monument, 111 (record on 8/26) at Sells, 108 (one degree shy of the record on 8/27) at Picacho, 106 on 8/26 at Tucson International Airport, 105 on 8/25 and 8/26 at San Carlos and 103 on 8/25 at Cascabel.

Excessive Heat, Upper Gila River and Aravaipa Valleys

When
August 25, 10:00 AM MST to August 27, 8:00 PM MST
Where
Upper Gila River and Aravaipa Valleys forecast zone
Reported by
Mesonet
Coordinates
33.074, -109.563 (the zone’s center; the record gives no point)

Very hot high temperatures of 104 to 114 degrees, or 5 to 11 degrees above normal, occurred in the lower elevations of Pima, southeast Pinal, and northwest sections of Cochise and Graham counties August 25-27 and caused the High Heat Risk category to be reached. The highest temperatures at select locations during the period were 114 degrees (tied record on 8/27) at Ajo, 112 (both records on 8/26 and 8/27) at Organ Pipe Cactus National Monument, 111 (record on 8/26) at Sells, 108 (one degree shy of the record on 8/27) at Picacho, 106 on 8/26 at Tucson International Airport, 105 on 8/25 and 8/26 at San Carlos and 103 on 8/25 at Cascabel.

Heat, Eastern Cochise County Below 5000 Feet

When
August 26, 10:00 AM MST to 8:00 PM MST
Where
Eastern Cochise County Below 5000 Feet forecast zone
Deaths
1 direct, 0 indirect
Reported by
County Official
Coordinates
31.880, -109.751 (the zone’s center; the record gives no point)

Temperatures 5 degrees above normal, 95 to 100 degrees, occurred in the lower elevations of southeast Cochise County causing the Moderate Heat Risk category to be reached on August 26. The Pima County Medical Examiner confirmed that heat was the primary cause of death for one male found near Douglas.

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
Heat, Eastern Cochise County Below 5000 Feet2021-08-2620MaleOutside/Open AreasDirect

What these are

Excessive Heat
Heat at or above the local excessive heat warning criteria, or heat that caused deaths.
Heat
Heat below excessive heat criteria that still caused deaths, injuries or significant impacts.

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

The same day elsewhere

More

Every storm in Arizona in 2021Every state in 2021This day in weather historyWarnings in Arizona, August 2021

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: 983910, 983916, 983917, 983918, 983919, 983920, 983921, 983922.