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

2023-07-15 to 2023-07-30 · 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 in the Altar Valley and Santa Cruz County July 15-30. Record highs at Sasabe included 111 degrees on July 19-21; 109 on July 16-18 and 26-28. Record highs at the Nogales Airport included 108 degrees on July 20, 107 on July 18 and 106 on July 21. The Pima County Medical Examiner determined that heat was the primary cause of death for five individuals found in the desert during the period. Heat was determined to be a contributing factor for an elderly man with other health issues who died in his front yard in Rio Rico in July 21.

Wider weather episode

Persistent strong high pressure aloft created an extended period of very hot temperatures July 14-30 across southeast Arizona. High temperatures were 5 to 14 degrees above normal causing the Major Heat Risk category to be reached and numerous high temperatures to be established. Several dozen heat-related fatalities were reported by the Pima County Medical Examiner.

Source: NOAA Storm Events Database, event_id 1127089. Narrative written by the NWS forecast office that issued the report.