The National Weather Service has issued a heat advisory for most of Southern California, with an extreme heat warning for San Bernardino and Riverside counties. Temperatures are expected to be 20 to 35 degrees warmer than average, potentially breaking many heat records for March. The heatwave will peak between Tuesday and Friday in Los Angeles, Orange, Riverside, San Bernardino, and San Diego Counties. Forecasters warned of a high risk for heat illness, particularly in locations away from the coast. The National Weather Services also warned of the potential for high temperatures, with temperatures expected to reach into the mid-90s and low-100s away from shore. The temperature is expected to drop on Saturday, with daytime high temperatures falling to 84.