San Diego woke up to clear skies and a comfortable 57°F at Lindbergh Field today, but the calm start is not sticking around for long. The National Weather Service has issued an Extreme Heat Watch from Monday morning, March 16, through Friday evening, March 20, with a big warmup on the way after a relatively mild weekend. Coastal commuters can expect patchy fog, while inland neighborhoods start creeping into the 70s and low 80s ahead of the main heat next week.
Foggy Mornings, Sunny Afternoons
The marine layer is expected to rebuild over the coastal waters late Saturday, pushing low clouds and patchy, at times dense, fog onto beaches and coastal mesas overnight into Sunday morning, March 15. The fog should thin by mid-morning, leaving mostly sunny afternoons and highs near 75 in the city and along the immediate coast this weekend. Early-morning visibility drops could slow seaside commutes and cause occasional delays at San Diego International.
Midweek Heat Risk
By next Monday, March 16, conditions start to turn sharply warmer as offshore flow sets up and a building ridge sends temperatures well above normal. The Extreme Heat Watch covers most coastal and inland areas, with daytime highs climbing into the 80s by Monday and into the upper 80s to near 90 across many inland neighborhoods by midweek. Desert and lower-desert areas may reach 100° or higher later in the week. Record March highs are possible away from the immediate coast, according to the National Weather Service San Diego.
Afternoon Winds And Timing
Breezy west and southwest winds will pick up across the mountains and deserts this afternoon, with gusts around 30-40 mph in exposed passes and canyons. Those winds should ease somewhat on Sunday as offshore flow becomes more widespread. Overnight lows will hold in the mid-50s through the midweek stretch, which means inland areas may get only limited nighttime relief once the heat really settles in. If you have outdoor plans, aim for mornings and evenings and try to avoid strenuous activity during the hottest parts of the day between next Tuesday, March 17, and Friday, March 20.
How To Stay Safe
During the watch period, drink plenty of water, keep strenuous activity to a minimum during peak afternoon heat, and spend time in air-conditioned spaces when possible. Check on elderly neighbors and people with health conditions, and never leave children or pets in parked cars, even for a short time. For a list of public cooling sites and libraries, see the SDG&E Cool Zones.
Forecasters may upgrade the Extreme Heat Watch to a warning or add new advisories as the pattern evolves, so check updated local forecasts before outdoor events and build in extra time for any coastal morning commutes over the weekend.
