Name: Heat in Arizona, September 18, 2023
Start: 2023-09-18T11:00
End: 2023-09-18T19:00
Location: Arizona

Where it happened

Every event with a place to put it; 1 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: 1

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.

Hot temperatures around 8 degrees above normal caused the Moderate Heat Risk category to be reached. One heat-related fatality was reported by the Pima County Medical Examiner in the Tumacacori-Carmen area.

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 Sep 18, 8:54 AM MST, 2 hours 6 minutes earlier.

Area forecast discussion, Sep 18, 8:54 AM MST, 2 hours 6 minutes before

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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

1 heat. Local standard time, as filed.

Heat, Upper Santa Cruz River and Altar Valleys

When: September 18, 11:00 AM MST to 7:00 PM MST
Where: Upper Santa Cruz River and Altar Valleys forecast zone
Deaths: 0 direct, 1 indirect
Reported by: County Official
Coordinates: 31.812, -111.318 (the zone’s center; the record gives no point)

Hot temperatures around 8 degrees above normal caused the Moderate Heat Risk category to be reached in northern Santa Cruz County where temperatures topped out in the upper 90s. The Pima County Medical Examiner determined that heat was a contributing factor in the death an elderly individual in their Tumacacori-Carmen 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.

Event	Date	Age	Sex	Where	Kind
Heat, Upper Santa Cruz River and Altar Valleys	2023-09-18	95	Male	Outside/Open Areas	Indirect

What these are

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 2023 Every state in 2023 This day in weather history Warnings 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: 1141665.