San Diego County is heading into a hot, humid stretch as monsoon moisture moves into the region, bringing tropical-feeling weather that is expected to last through at least mid-August. On Thursday, temperatures across the county are expected to run up to five degrees above average, while the mountains and deserts also keep unusually warm overnight lows.
That matters today because the shift comes with active heat alerts and a forecast that changes fast depending on where people are standing. In the deserts, an Extreme Heat Warning remains in effect through Saturday, with highs expected to reach 109 to 115 degrees. Mountain areas are under a Heat Advisory, with temperatures climbing into the 80s and 90s, while the coast is forecast to stay in the upper 70s and low 80s.
The same pattern that is raising the heat is also making the atmosphere more unstable. Sunshine is expected to dominate, but marine layer clouds near the coast and increasing afternoon cloud buildup over the mountains and deserts could help isolated showers and thunderstorms develop on Thursday. A stronger chance of those storms is expected on Sunday and Monday, leaving San Diegans to deal with both blistering heat and the possibility of sudden wet weather.
That mix is the hard part of this forecast. The deserts can stay under an Extreme Heat Warning even as the chance of isolated showers and thunderstorms rises, which means the region is not getting a clean break from danger. Warm nights in the mountains and deserts offer little relief, and the moisture surge only makes the forecast harder to read for people trying to plan around outdoor work, travel or power use.
Experts are urging residents in San Diego County to stay hydrated, avoid outdoor activity during peak heat and never leave children or pets in vehicles. They are also telling people to check vehicles for fire hazards, trim vegetation around homes and keep emergency supplies ready. The next key change is whether Thursday's scattered storm threat stays isolated or grows more widespread when Sunday and Monday arrive.
While the weather is the main story, the same day also included unrelated national political news involving a Senate Committee on Homeland Security and Governmental Affairs vote tied to Dr. Anthony Fauci and the Justice Department. For residents in San Diego County, though, the immediate issue is simpler: the heat is already building, the air is getting stickier, and the desert warning does not let up until Saturday.
