East County News Service
May 8, 2026 (San Diego County) — A powerful high-pressure system will settle over Southern California, pushing temperatures in San Diego’s desert regions toward unseasonably extreme temperatures this weekend.
The National Weather Service has officially upgraded its Extreme Heat Watch to an Extreme Heat Warning for the low deserts, effective 10 a.m. Sunday through 8 p.m. Monday.
Residents in the inland valleys and mountains are also under a Minor to Moderate Heat Risk advisory, with temperatures expected to run 10 to 20 degrees above seasonal norms in the farthest inland locations.
While the entire county will feel the heat, the low deserts — including Anza-Borrego State Park and Ocotillo Wells — are facing the most severe conditions. High temperatures in these areas are projected to peak between 103°F and 109°F from Sunday through Tuesday.
For those in the inland valleys, such as Escondido, Ramona, and Alpine, the mercury is expected to climb into the upper 80s to low 90s at peak, posing a significant threat to those without adequate air conditioning. Even mountain communities like Julian and Mt. Laguna will see uncharacteristic heat, with Moderate Heat Risk levels forecast early next week.
The National Interagency Fire Center has already flagged the Southwest for “above normal significant fire potential” this month, citing the rapid drying of “flash fuels” like grass and brush. With the heat spike and low humidity, the risk of a fast-moving brush fire is significantly elevated.
County officials are urging residents to utilize the “Cool Zone” program, particularly for the elderly, the homeless, and those living in older homes without cooling systems.
All San Diego Public Library branches and many Parks and Recreation centers are designated as safe places to escape the heat during their standard business hours. The County says not to wait until you feel dizzy or thirsty to seek shade. Heat exhaustion can set in rapidly, especially when temperatures exceed 100°F. Check on the elderly and those living along at least twice a day; ensure animals have plenty of water and shade; avoid walking dogs on hot asphalt; drink more water than usual; and if someone stops sweating and becomes confused, call 9-1-1 immediately — this is a sign of life-threatening heat stroke.
Forecast at a Glance (Peak Sunday–Monday)
Coast: 5 to 10°F above normal (Highs in the low-to-mid 70s)
Inland Valleys: 10 to 20°F above normal (Highs in the upper 80s to low 90s)
Mountains: Minor to Moderate Heat Risk (Highs in the mid-80s to low 90s)
Deserts: Highs of 103°F to 109°F — Extreme Heat Warning in effect
For the most up-to-date local forecasts and cooling center locations, visit weather.gov/sandiego or Alert San Diego.