Portions of San Diego County will be under a heat advisory Friday as a mini heat wave sends temperatures in the region up to 20 degrees above average.
A National Weather Service heat advisory for coastal areas and the valleys is scheduled to remain in effect from 10 a.m. to 8 p.m. as offshore flow and building high pressure usher in high temperatures of 87 to 92 degrees at the beaches, 96 to 101 degrees inland and 99 to 104 degrees in the valleys.
"The hottest conditions approaching 105 will be in the Inland Empire, with temperatures nearly as hot for the inland portions of Orange and San Diego counties," according to the weather service. "A heat advisory continues for all areas west of the mountains through early this evening and that definitely looks on target."
Elsewhere in the county, warmer and mostly sunny conditions are in Friday's forecast along with high temperatures of 85 to 95 degrees in the mountains and around 99 in the deserts.
Weather service meteorologists said it would cool down over the weekend, but not by much. High temperatures of 5 to 15 degrees above average are expected Saturday and Sunday. Higher than normal temperatures are expected to continue into next week.
Forecasters urged residents to protect themselves and their loved ones against dehydration, heat stroke and other heat-related illnesses. They are advised to stay well-hydrated, avoid working in the sun, check on neighbors and relatives — especially the elderly — and provide plenty of water to pets and livestock.
Authorities also warned against leaving children or pets in parked cars, which can quickly become death traps in high heat.