The extreme late-summer heatwave that has brought triple-digit temperatures to parts of the San Diego area is expected to roast the region through the Labor Day weekend.
The hot spell and accompanying low humidity and gusty winds out of the east prompted the National Weather Service to issue a “red flag” wildfire warning for the inland valleys and mountains, effective from 10 a.m. Saturday to 6 p.m. Sunday.
The alert signifies a likelihood of critical combustion hazards that can lead to “extreme fire behavior.”
Excessive heat warnings for the coasts, valleys, deserts and mountains were extended to 8 p.m. Sunday.
By the end of Saturday, the NWS said all-time record-high temperatures were recorded in El Cajon, 114 degrees; Alpine, 113 degrees; Ramona, 112 degrees; Borrego Springs, 117 degrees; and Escondido, 111 degrees.
— NWS San Diego (@NWSSanDiego) September 6, 2020
By 1 p.m. Saturday, Borrego was at 115 degrees, Alpine 112, Ramona 110, and Valley Center and Jamul 109.
Along the coast, temperatures were in the high 80s, with Oceanside at 84, Encinitas 87, La Jolla 88, San Diego 86, and Imperial Beach 88.
Expected high temperatures along the coast Saturday will be 87-92 degrees with overnight lows 69-77, forecasters said. Inland valley highs will be 108-113 with overnight lows of 74-81. Mountain highs will be 100-105 with overnight lows of 68-76, and desert highs will be 118-123 with overnight lows of 83-88.
Air moisture levels will drop to the 15-20% range on Saturday and Sunday with poor overnight recovery, according to meteorologists. Winds out of the east are expected to reach sustained speeds between 15-25 mph, with gusts potentially reaching 30-40 mph in the southern reaches of the county.
Excessive heat warnings, meanwhile, will be in effect in the western valleys, the mountains, and the deserts through 8 p.m. Monday; and in coastal areas from 10 a.m. Saturday through 8 p.m. Monday.
On Friday, the mercury climbed into the high 80s along the coast and past the 100 mark in the inland valleys, mountains, and deserts, the weather service reported.
To beat the heat, people should drink plenty of fluids, stay out of the sun during the hottest parts of the day and check on potentially at-risk relatives and neighbors, the NWS advised. Also, children, seniors, and pets should be never be left unattended in a vehicle, with car interiors able to “reach lethal temperatures in a matter of minutes,” according to the federal agency.
To help sweltering residents, the county is offering nine air-conditioned cooling centers in Alpine, Borrego Springs, Fallbrook, Lakeside, Potrero, Ramona, Santa Ysabel, Spring Valley, and Valley Center.
Due to the coronavirus, mandatory mask-wearing and social-distancing protocols are enforced in the facilities. A full list of the locations, which will be will be open from noon to 5 p.m. daily throughout the Labor Day weekend, can be found at https://www.sandiegocounty.gov/content/sdc/hhsa/programs/ais/cool_zones.html.
City News Service contributed to this report
Updated at 2 and 9:40 p.m. Sept. 5, 2020