Websan diego weather forecasts. Weba few to around 5 degrees cooler than monday, 10 to 15 degrees above average for portions of the mountains, deserts, and inland valleys. Weba few to around 5 degrees cooler than monday, 10 to 15 degrees above average for portions of the mountains, deserts, and inland valleys.

Excessive heat warnings in effect through 8 pm monday for the low deserts, inland empire, san diego valleys, and santa ana mountains. Heat advisories in effect through 8 pm monday for the mountains in san diego, riverside, and san bernardino counties. Otherwise, mostly cloudy, with a low around 63. North wind around 5 mph. Patchy fog before 8am.

Patchy fog before 8am.