SAN DIEGO (KGTV) — A prolonged heat wave is gripping San Diego County this weekend, bringing unusually hot temperatures all the way to the beaches as Santa Ana winds limit the cooling influence of the Pacific Ocean.
High pressure strengthening over Southern California, combined with offshore flow, will send temperatures well above normal across areas west of the mountains. The National Weather Service says the heat will peak this weekend, with coastal and inland valley temperatures running roughly 15 to 25 degrees above normal in some locations.
Saturday is expected to be the hottest day of the week.
Even San Diego County's coastline will offer little relief. Temperatures could reach the upper 90s to low triple digits within just a mile or two of the beaches.
Typically, San Diego's marine layer and afternoon sea breeze help keep coastal communities significantly cooler than inland areas. This weekend, however, high pressure is keeping the marine layer extremely shallow while Santa Ana winds push warm, dry air toward the coast.
That will also keep skies mostly clear, with little to no coastal fog or low clouds expected.
The heat follows an already unusually warm Friday, when several locations across Southern California tied or broke daily temperature records. Some inland valley locations Saturday morning were already running 10 to 15 degrees warmer than the same time Friday.
Santa Ana winds continue
The heat will be accompanied by gusty Santa Ana winds through the weekend.
The strongest winds are expected around the mountains, foothills and portions of the inland valleys. Gusts could reach around 35 to 45 mph in wind-prone locations.
The combination of hot temperatures, dry conditions and gusty offshore winds will also increase fire weather concerns across inland portions of the county.
When does San Diego cool down?
The Santa Ana winds are expected to weaken Monday, but the heat will not disappear with them.
Some minor relief could reach the immediate coastline by Tuesday as a weak sea breeze begins to return. Cooling will then gradually spread farther inland through the middle of next week.
The inland valleys, however, could continue reaching the upper 90s to low triple digits through Thursday.
A meaningful return of San Diego's marine layer and coastal low clouds is unlikely before Wednesday night or Thursday morning.
More noticeable cooling could finally arrive beginning next Friday as high pressure weakens and a trough approaches Southern California. Even then, some western inland valleys could remain as much as 15 degrees above normal.
SAN DIEGO COUNTY HIGH TEMPERATURE RANGES
COAST: 92–102°
INLAND VALLEYS: 92–101°
MOUNTAINS: 73–83°
DESERTS: 95–99°
