Arizona, 2023

Excessive Heat in Arizona, September 9 to 10, 2023

September 9 to 10, 2023 · NWS TWC · 5 events in 5 counties and zones

Very hot temperatures were observed across southeast Arizona September 9 and 10. High temperatures were 10 to 14 degrees above normal causing the Major Heat Risk categories to be reached.

Where it happened

Every event with a place to put it; 5 filed by county or forecast zone are drawn at its center, in a lighter ring. Tap one for its entry below.

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The toll

Deaths
4
Injuries
0
Property damage
None recorded
Crop damage
None recorded
Events
5

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 observed across southeast Arizona September 9 and 10. High temperatures were 10 to 14 degrees above normal causing the Major Heat Risk categories to be reached. A total of four heat-related fatalities were reported by the Pima County Medical Examiner.

The radar

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

Open the radar archive at this moment

Event by event

5 excessive heat. Local standard time, as filed.

Excessive Heat, Western Pima County

When
September 9, 10:00 AM MST to September 10, 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 temperatures of 10 to 14 degrees above normal caused the Major Heat Risk category to be reached across western Pima and southeast Pinal counties September 9-10. Record highs at Ajo were 115 and 113 degrees, respectively. Record highs at Organ Pipe Cactus National Monument were 111 degrees on both days. Record highs at Picacho Peak were 109 and 110 degrees and records at San Manuel were 101 and 106 degrees.

Excessive Heat, South Central Pinal County

When
September 9, 10:00 AM MST to September 10, 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 temperatures of 10 to 14 degrees above normal caused the Major Heat Risk category to be reached across western Pima and southeast Pinal counties September 9-10. Record highs at Ajo were 115 and 113 degrees, respectively. Record highs at Organ Pipe Cactus National Monument were 111 degrees on both days. Record highs at Picacho Peak were 109 and 110 degrees and records at San Manuel were 101 and 106 degrees.

Excessive Heat, Southeast Pinal County

When
September 9, 10:00 AM MST to September 10, 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 temperatures of 10 to 14 degrees above normal caused the Major Heat Risk category to be reached across western Pima and southeast Pinal counties September 9-10. Record highs at Ajo were 115 and 113 degrees, respectively. Record highs at Organ Pipe Cactus National Monument were 111 degrees on both days. Record highs at Picacho Peak were 109 and 110 degrees and records at San Manuel were 101 and 106 degrees.

Excessive Heat, Tohono O Odham Nation

When
September 9, 10:00 AM MST to September 10, 8:00 PM MST
Where
Tohono O Odham Nation forecast zone
Deaths
3 direct, 0 indirect
Reported by
County Official
Coordinates
32.501, -111.567 (the zone’s center; the record gives no point)

Very hot temperatures of 10 to 14 degrees above normal caused the Major Heat Risk category to be reached across the Tohono O'odham Nation September 9-10. Record highs at Sells were 110 and 109 degrees, respectively. The Pima County Medical Examiner determined that heat was the primary cause of death for three individuals found in the desert on the 9th in the Santa Rosa, Topawa and San Ignacio areas.

Excessive Heat, Tucson Metro Area

When
September 9, 10:00 AM MST to September 10, 8:00 PM MST
Where
Tucson Metro Area forecast zone
Deaths
0 direct, 1 indirect
Reported by
County Official
Coordinates
32.097, -111.790 (the zone’s center; the record gives no point)

Very hot temperatures around 10 degrees above normal caused the Major Heat Risk category to be reached across the Tucson Metro area September 9-10. Record highs at Tucson International Airport were 108 and 111 degrees, respectively. The Pima County Medical Examiner determined that heat was a contributing factor in the death an elderly individual in their Tucson back yard. Heart disease was a complicating factor in this fatality.

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, Tohono O Odham Nation2023-09-0918MaleOutside/Open AreasDirect
Excessive Heat, Tohono O Odham Nation2023-09-0926MaleOutside/Open AreasDirect
Excessive Heat, Tohono O Odham Nation2023-09-0933MaleOutside/Open AreasDirect
Excessive Heat, Tucson Metro Area2023-09-0986MaleOutside/Open AreasIndirect

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 2023Every state in 2023This day in weather historyWarnings in Arizona, September 2023

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 2026-10-01. Each event’s entry at NCEI: 1141657, 1141658, 1141659, 1141660, 1141661.