A wildfire roaring through the 4S Ranch area has forced evacuation orders for more than 20,000 homes, but so far none have burned.
San Diego's Emergency Operations Center says most of the homes are in the city and northern San Diego County.
The 700-acre blaze, north of state Route 56 and west of Interstate 15, erupted Tuesday morning. It's fueled by canyons full of brush and pushed by hot, dry winds.
At least two high schools and one elementary school also were evacuated, police Detective Gary Hassen said.
Another fire destroyed a mobile home and prompted the evacuation of five homes in the rural town of Campo in southern San Diego County before it was largely surrounded, state fire Capt. Kendal Bortisser said.
A high-pressure system has created dangerously hot, dry conditions around the state, with temperatures far above normal for spring and gusty winds possible through Wednesday.