Inland temperatures could top 100 degrees Friday, Oct. 2, as a weeklong heat wave driven by high pressure and Santa Ana winds raises wildfire danger across San Diego County.

The National Weather Service issued an Extreme Heat Warning running from 10 a.m. Friday through 8 p.m. Thursday, Oct. 8. The agency projects Saturday highs of 97 degrees in nearby Mira Mesa, the closest named forecast point to Poway and Rancho Bernardo, the San Diego Union-Tribune reported. San Diego's average seasonal high is 76 degrees.

Wind gusts of 25 to 40 mph are expected inland, with periodic gusts up to 50 mph in the mountains, according to the NWS. The combination of triple-digit heat, low humidity and gusty winds sharply increases wildfire risk in a region that has not had significant rain since June.

"We'll have this warm weather late into next week," Kyle Wheeler, a National Weather Service forecaster, told the Union-Tribune.

ABC 10News reported humidity levels could drop to between 15% and 25%. The Climate Prediction Center is forecasting an 80% to 90% chance of above-normal temperatures through mid-October, and the Extreme Heat Warning may be extended.

SDG&E warns of possible power shutoffs

San Diego Gas & Electric said weather conditions could force public safety power shutoffs (PSPS), in which the utility turns off electricity in high-risk areas to prevent downed power lines from sparking wildfires. SDG&E identified a window of concern from 5 a.m. Friday, Oct. 2, through 6 p.m. Monday, Oct. 5.

The utility notified more than 35,000 customers in foothill and mountain communities that shutoffs could begin as early as Friday morning, NBC 7 San Diego reported. Poway is among 18 communities on SDG&E's potential shutoff list, alongside Alpine, El Cajon, Fallbrook, Julian, Lakeside, Ramona, Valley Center and others.

SDG&E said in a statement that its teams are monitoring conditions around the clock and have positioned crews across the region.

Grid operator preparing but no Flex Alert yet

The California Independent System Operator (CAISO), which manages the high-voltage transmission system for about 80% of California, issued restricted maintenance operations directives calling on Southern California utilities to postpone routine equipment work and keep all grid assets online. Those directives cover 10 a.m. to 10 p.m. Monday and Tuesday, the Union-Tribune said.

As of Thursday, Oct. 1, CAISO's daily outlook showed 62,184 megawatts of grid capacity available against a forecasted Friday peak demand of 41,035 megawatts. No Flex Alert has been issued. The grid operator said on X on Thursday, Oct. 1, that it is not forecasting supply shortfalls but wanted to prepare consumers in case a voluntary conservation request becomes necessary.

What Poway residents should know

Poway sits in an area Cal Fire designated as a Very High Fire Hazard Severity Zone under an updated map released in March 2025. Winds are expected to diminish after Sunday, Oct. 4, according to the NWS, but above-normal heat is forecast to persist well into the following week.

SDG&E urged customers in potential shutoff areas to charge devices, prepare emergency kits and check on heat-vulnerable neighbors. Customers can monitor shutoff status on the utility's website.