High temperatures continue to increase on the Central Coast Cecil Horton posted this on Dave Hovde's Facebook page. and last updated 2021-07-11 19:01:41-04 The National Weather Service has issued an excessive heat warning that remains in effect until 9 pm Monday for San Luis Obispo County Interior Valleys and Mountains, as well as the Cuyama and Antelope Valleys. Dangerously hot conditions are expected with temperatures of 103 to 115 degrees, today being the hottest. Overnight temperatures will be 75 to 85 degrees in warmer valleys. The National Weather Service issued a heat advisory that will remain in effect until 9pm Monday for The Mountains of Los Angeles, Ventura, and Santa Barbara Counties excluding the Santa Monica Range. In these area expect to see Hot conditions with temperatures of 100 to 109 degrees, with today being the hottest. Overnight temperatures will be 70 to 80 degrees.