LOS ANGELES (CNS) – Summer may have ended, but that doesn’t mean we’re done with the heat.

Forecasters say temperatures will be on the rise through the weekend, leading to excessive heat watches that will be in effect for most of the Southland early next week.

According to the National Weather Service (NWS), a high-pressure system is building over the region, bringing temperatures that are expected to be five to 10 degrees above normal by Saturday.

“Temperatures will be hottest on Monday and Tuesday when highs push into the 90s to around 105 degrees across the interior coastal plain, valleys, mountains and deserts,” according to the NWS. “The coastal and inland valleys of Los Angeles County and nearby Ventura County will be especially warm with excessive heat conditions likely on those days.”

The NWS issued an excessive heat watch for the bulk of the Southland that will be in effect from Monday morning through Wednesday evening, warning of “dangerously hot conditions” in many areas, particularly the valleys.

In Orange County, forecasters also issued excessive heat watches that will be in place Monday morning through Wednesday evening for inland and coastal areas. According to the NWS, temperatures could reach triple-digits inland in cities such as Santa Ana, Anaheim, Irvine and Fullerton, while coastal areas could reach into the 90s.

“Be prepared to drink plenty of fluids, stay in an air-conditioned room, stay out of the sun and check up on relatives and neighbors,” the NWS advised. “Young children and pets should never be left unattended in vehicles under any circumstances.”