A fire burned a small area near a church and a preschool center in the area of 28th Street and State Route 94 on Monday.
San Diego Fire-Rescue Department crews and California Highway Patrol officers were called to the area for a vegetation fire.
Flames scorched an eighth of an acre as of 10 a.m.
However, a column of smoke was seen as far away as Cowles Mountain.
San Diego police and the CHP shut down the freeway ramp while firefighters extinguished the hot spots.
Record-breaking temperatures and near-zero humidity were in the forecast for San Diego County.
Images: Fire Burns South of Downtown San Diego
A red flag warning was issued, advising that if a fire starts there is the potential for "very rapid spread,'' the National Weather Service said.
No other information was available.