Arizona, 2020Excessive Heat and Heat in Arizona, September 4 to 7, 2020
September 4 to 7, 2020 · NWS TWC · 8 events in 8 counties and zones
Very hot temperatures were experienced in the lower elevations of southeast Arizona from September 4th-7th. Many locations approached or exceeded 110 degrees and set new daily record high temperatures.
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.
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- Deaths
- 5
- 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.
Very hot temperatures were experienced in the lower elevations of southeast Arizona from September 4th-7th. Many locations approached or exceeded 110 degrees and set new daily record high temperatures. The Pima County Medical Examiner confirmed that heat was the primary cause of death for five individuals found in the desert in Pima and Cochise counties during the period.
Excessive Heat, Western Pima County
- When
- September 4, 10:00 AM MST to September 7, 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 10 to 13 degrees above normal occurred in the lower elevations of southeast Arizona, causing the High Heat Risk category to be reached September 4 through September 7. Record high temperatures were tied or set at most locations on multiple days during the period. The hottest record temperatures during this stretch were 115 degrees at Ajo on September 6; 114 at Ajo on the 4th and 5th, and at Picacho on the 5th; 113 at Picacho on the 6th; and 112 at Picacho and Sells on the 4th; 110 at Tucson International Airport on the 4th; 109 at Green Valley on the 4th and 5th; and 107 at Fort Thomas on the 5th, and at Safford Airport on the 7th. The Pima County Medical Examiner confirmed that heat was the primary cause of death for two individuals on the Tohono O'odham Nation--a female east of Sells on the 4th and a male north of Hickiwan on the 6th.
Excessive Heat, Tohono O Odham Nation
- When
- September 4, 10:00 AM MST to September 7, 8:00 PM MST
- Where
- Tohono O Odham Nation forecast zone
- Deaths
- 2 direct, 0 indirect
- Reported by
- County Official
- Coordinates
- 32.501, -111.567 (the zone’s center; the record gives no point)
Very hot temperatures 10 to 13 degrees above normal occurred in the lower elevations of southeast Arizona, causing the High Heat Risk category to be reached September 4 through September 7. Record high temperatures were tied or set at most locations on multiple days during the period. The hottest record temperatures during this stretch were 115 degrees at Ajo on September 6; 114 at Ajo on the 4th and 5th, and at Picacho on the 5th; 113 at Picacho on the 6th; and 112 at Picacho and Sells on the 4th; 110 at Tucson International Airport on the 4th; 109 at Green Valley on the 4th and 5th; and 107 at Fort Thomas on the 5th, and at Safford Airport on the 7th. The Pima County Medical Examiner confirmed that heat was the primary cause of death for two individuals on the Tohono O'odham Nation--a female east of Sells on the 4th and a male north of Hickiwan on the 6th.
Excessive Heat, Tucson Metro Area
- When
- September 4, 10:00 AM MST to September 7, 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 temperatures 10 to 13 degrees above normal occurred in the lower elevations of southeast Arizona, causing the High Heat Risk category to be reached September 4 through September 7. Record high temperatures were tied or set at most locations on multiple days during the period. The hottest record temperatures during this stretch were 115 degrees at Ajo on September 6; 114 at Ajo on the 4th and 5th, and at Picacho on the 5th; 113 at Picacho on the 6th; and 112 at Picacho and Sells on the 4th; 110 at Tucson International Airport on the 4th; 109 at Green Valley on the 4th and 5th; and 107 at Fort Thomas on the 5th, and at Safford Airport on the 7th. The Pima County Medical Examiner confirmed that heat was the primary cause of death for two individuals on the Tohono O'odham Nation--a female east of Sells on the 4th and a male north of Hickiwan on the 6th.
Excessive Heat, South Central Pinal County
- When
- September 4, 10:00 AM MST to September 7, 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 10 to 13 degrees above normal occurred in the lower elevations of southeast Arizona, causing the High Heat Risk category to be reached September 4 through September 7. Record high temperatures were tied or set at most locations on multiple days during the period. The hottest record temperatures during this stretch were 115 degrees at Ajo on September 6; 114 at Ajo on the 4th and 5th, and at Picacho on the 5th; 113 at Picacho on the 6th; and 112 at Picacho and Sells on the 4th; 110 at Tucson International Airport on the 4th; 109 at Green Valley on the 4th and 5th; and 107 at Fort Thomas on the 5th, and at Safford Airport on the 7th. The Pima County Medical Examiner confirmed that heat was the primary cause of death for two individuals on the Tohono O'odham Nation--a female east of Sells on the 4th and a male north of Hickiwan on the 6th.
Excessive Heat, Southeast Pinal County
- When
- September 4, 10:00 AM MST to September 7, 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 10 to 13 degrees above normal occurred in the lower elevations of southeast Arizona, causing the High Heat Risk category to be reached September 4 through September 7. Record high temperatures were tied or set at most locations on multiple days during the period. The hottest record temperatures during this stretch were 115 degrees at Ajo on September 6; 114 at Ajo on the 4th and 5th, and at Picacho on the 5th; 113 at Picacho on the 6th; and 112 at Picacho and Sells on the 4th; 110 at Tucson International Airport on the 4th; 109 at Green Valley on the 4th and 5th; and 107 at Fort Thomas on the 5th, and at Safford Airport on the 7th. The Pima County Medical Examiner confirmed that heat was the primary cause of death for two individuals on the Tohono O'odham Nation--a female east of Sells on the 4th and a male north of Hickiwan on the 6th.
Excessive Heat, Upper Gila River and Aravaipa Valleys
- When
- September 4, 10:00 AM MST to September 7, 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 temperatures 10 to 13 degrees above normal occurred in the lower elevations of southeast Arizona, causing the High Heat Risk category to be reached September 4 through September 7. Record high temperatures were tied or set at most locations on multiple days during the period. The hottest record temperatures during this stretch were 115 degrees at Ajo on September 6; 114 at Ajo on the 4th and 5th, and at Picacho on the 5th; 113 at Picacho on the 6th; and 112 at Picacho and Sells on the 4th; 110 at Tucson International Airport on the 4th; 109 at Green Valley on the 4th and 5th; and 107 at Fort Thomas on the 5th, and at Safford Airport on the 7th. The Pima County Medical Examiner confirmed that heat was the primary cause of death for two individuals on the Tohono O'odham Nation--a female east of Sells on the 4th and a male north of Hickiwan on the 6th.
Excessive Heat, Upper Santa Cruz River and Altar Valleys
- When
- September 4, 10:00 AM MST to 8:00 PM MST
- Where
- Upper Santa Cruz River and Altar Valleys forecast zone
- Deaths
- 1 direct, 0 indirect
- Reported by
- County Official
- Coordinates
- 31.812, -111.318 (the zone’s center; the record gives no point)
Hot temperatures 12 to 14 degrees above normal occurred in southeast Pima County and Santa Cruz County, causing the High Heat Risk category to be reached September 4. Record high temperatures were set at Sasabe (105) and Nogales Airport (104). The Pima County Medical Examiner confirmed that heat was the primary cause of death for one male near Keystone Peak about 10 miles west of Green Valley.
Heat, Eastern Cochise County Below 5000 Feet
- When
- September 4, 10:00 AM MST to 8:00 PM MST
- Where
- Eastern Cochise County Below 5000 Feet forecast zone
- Deaths
- 2 direct, 0 indirect
- Reported by
- County Official
- Coordinates
- 31.880, -109.751 (the zone’s center; the record gives no point)
Hot temperatures 6 to 9 degrees above normal occurred in southeast Cochise County, causing the Moderate Heat Risk category to be reached September 4. A record high temperature of 105 degrees was set at McNeal. The Pima County Medical Examiner confirmed that heat was the primary cause of death for two males near Douglas on the 4th.
- 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.
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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: 919371, 919374, 919377, 919378, 919380, 919381, 919384, 919391.