LOS ANGELES (CBSLA) — After an extended cool and rainy winter, the summer heat is back with a vengeance.

A heat advisory goes into effect for most of Southern California starting at 10 a.m., when temperatures are forecast to be in the upper 90s to around 104, according to the National Weather Service.

READ MORE: Palisades Fire: Hundreds Under Evacuation, 1 Detained For Questioning In Arson Investigation

Several Inland Empire communities broke heat records Monday. Hemet hit a high of 103 degrees, breaking the previous record of 100 reached in 1918. In Thermal, the high hit 113 degrees, two degrees higher than the old record in 2008.

Ontario reached a scorching 107 degrees, blowing way past the old record of 89 set in 2018, while the mountain community of Idyllwild hit a high of 89 degrees, a degree higher than the old record of 88 set in 1973.

READ MORE: Israel Continues Air Assault On Gaza Strip, Almost 200 Palestinians Killed

Tuesday’s heat started out early, with some San Fernando Valley and Inland Empire areas waking up to 70 degrees before even 6 a.m.

A heat advisory will be in effect for Ventura, Los Angeles and Orange counties, and most of the Inland Empire, warning of heat capable of causing heat-related illnesses. In the Coachella Valley, an excessive heat warning will be in effect through Wednesday night.

MORE NEWS: Man Shot, Killed Outside Hacienda Heights Gas Station

Los Angeles is forecast to reach a high of 93 degrees, with the valleys expected to hit highs of 103 or more. Even the beaches will be toasty, flirting with 80-degree temperatures.