Excessive Heat — San Diego County Valleys, California

2018-07-06 to 2018-07-07 · San Diego County Valleys, California

Event narrative

Intense heat on July 6 (and offshore flow) resulted in breezy east winds and a high of 117F at Ramona ASOS. The previous record high was 111F. At Escondido the high was 112 and Santee 110, these were just shy of all-time highs. San Diego Public Health and 211 services share statistic which showed a sharp jump in heat related 911 and 211 information calls. 211 San Diego can provide vouchers for those in need of cool shelter during heat waves. The destructive West Fire also occurred in Alpine, San Diego County on July 6. Alpine had highs of 109 and 104 for July 6 and 7th with wind gusts to 30 mph.

Wider weather episode

Strong broad upper level high pressure centered over Nevada and unusual weak offshore flow in July brought extreme hot temperatures and dry conditions to Southern California from July 6th through 8th. Inland Orange County, San Diego Valleys, Inland Empire and the deserts experienced the most extreme temperatures. July 6th was the hottest day during this event, with Thermal and Chino reaching 120 degrees, and San Bernardino and Riverside Airport reaching 118 degrees. July 7th and 8th remained quite hot -- only a few degrees cooler than July 6th. Heat began to subside significantly on July 9th.

Source: NOAA Storm Events Database, event_id 783080. Narrative written by the NWS forecast office that issued the report.