Southern Californians face one more day of sky-high temperatures before they get some relief from days of draining, triple-digit heat.
The region should expect "dangerously hot weather" Tuesday, with an excessive heat warning in Los Angeles County valleys in effect until 7 p.m, according to the National Weather Service. Downtown Los Angeles broke a nearly-century-old record for the date with a high of 103 degrees.
Record high temperatures are possible Tuesday. The record high for Sept. 16 in downtown Los Angeles is 103 degrees, set in 1909. Other Sept. 16 record highs include 99 (1966) in Long Beach; 105 (1984) in Burbank; 104 (1951) in Lancaster; and 91 (1958) in Camarillo.
Wednesday will bring relatively cool weather, but highs will remain in the 90s in many places.
Tuesday brought more than punishing heat to the Southland. The Inland Empire was slammed by heavy rainfall and severe thunderstorms. A flash flood warning was issued for parts of Riverside County.
A lightning strike in Crestline caused a fire at a home, the San Bernardino County Fire Department said.
The region also is under a red flag fire weather warning through 9 p.m. The warning indicates the possibility of explosive fire growth in the mountains of Los Angeles County, Ventura County and Santa Barbara County, where "sundowner" winds -- hot, gale-force winds that make firefighting difficult to impossible -- could stoke flames.
Monday's record heat also led to record power use as air conditioners taxed the electric grid. The Los Angeles Department of Water and Power reported record high power demand Monday during the late-summer heat wave.
The LADWP is forecasting that it will break Tuesday's demand record and exceed 6,200 megawatts as heat-wave temperatures continue.