Excessive Heat — Upper Santa Cruz River and Altar Valleys, Arizona

2023-08-04 to 2023-08-06 · Upper Santa Cruz River and Altar Valleys, Arizona

Event narrative

Very hot temperatures of 8 to 13 degrees above normal caused the Major Heat Risk category to be reached across the Tohono O'odham Nation, southeast Pima County, and the lower elevations of Santa Cruz County August 4-6. Record highs at Sells included 109 degrees on August 4 and 5; and 107 at Nogales on August 5. The Pima County Medical Examiner determined that heat was the primary cause of death for four individuals found in the desert during the period; one northwest of Tubac on the 4th and three others on the Tohono O'odham Nation on the 5th in the Sells and Topawa areas.

Wider weather episode

High pressure aloft strengthened over Arizona and created a period of very hot temperatures August 4-6 across southeast Arizona. High temperatures were 8 to 13 degrees above normal causing the Major Heat Risk category to be reached and numerous high temperature records to be established. A total of nine heat-related fatalities were reported by the Pima County Medical Examiner.

Source: NOAA Storm Events Database, event_id 1134755. Narrative written by the NWS forecast office that issued the report.