Lightning strikes were reported in the San Diego County deserts Sunday morning, amid a dangerous heat wave that's expected to grip most of Southern California through next weekend.
"Showers and isolated t-storms continue to move northwestward this morning. Lightning strikes have been reported in the deserts in San Diego County and Riverside County in the past few hours, so please use caution and remember if thunder roars, go indoors," the National Weather Service's San Diego office tweeted Sunday morning.
The NWS' Sunday forecast called for temperatures up to 114 in the county's deserts and 101 in the mountains.
Get top local stories in San Diego delivered to you every morning. Sign up for NBC San Diego's News Headlines newsletter.
"Extreme heat will significantly increase the potential for heat related illnesses, particularly for those working or participating in outdoor activities," NWS forecasters warned. "Know the signs and symptoms of heat exhaustion and heat stroke. Wear light weight and loose fitting clothing when possible and drink plenty of water."
More heat-related stories:
Temperatures will be under the triple digit marker in the valleys and coastal areas with a 20% chance of precipitation.
"A brief surge of monsoonal moisture Sunday and Monday will bring mid level clouds and a slight chance of afternoon thunderstorms to the mountains and high deserts. The marine layer will continue to moderate the heat near the coast. Hot weather will continue through most of next week," forecasters said.