Southern California was bracing Monday for a heat wave expected to bring triple-digit temperatures to much of the region this week.

Driven by weak offshore winds and a heat dome over the southwestern United States, temperatures are forecast to rise over the course of the week before peaking Thursday and Friday. Portions of the Los Angeles Basin could reach 113 degrees by the weekend while the mercury could climb to 119 in the Coachella Valley.

“We are in what’s already the hottest time of the year climatically, and we are going to be 10 to 15 degrees above normal, in almost every area from the beach to the deserts,” said meteorologist Ryan Kittell of the National Weather Service’s Oxnard office.

Labor Day was already scorching in many communities, with the San Gabriel Valley forecast to hit 100 degrees and the western San Fernando Valley to see temperatures as high as 103. L.A. neighborhoods closer to the water were to enjoy relatively more moderate conditions in the 80s and low 90s.

Woodland Hills, traditionally the hottest place in L.A., was expected to have temperatures of up to 109 degrees Tuesday, 110 Wednesday and 113 Thursday before falling slightly to 111 on Friday.

In Santa Clarita, temperatures were expected to skyrocket from an uncomfortable 95 degrees on Monday to an oppressive 106 by Thursday. In Palm Springs, Labor Day temperatures of 107 to 111 degrees were to give way to temperatures of 114 to 118 degrees by Thursday.

Dangerously hot conditions were affecting a swath of the country including Nevada and Arizona. Kittell, of the National Weather Service in Oxnard, said that because days are shorter than in June and July, desert areas experience less sun and as a result, there are fewer differences in temperature between them and coastal communities.

He said people who live close to the beach and don’t have air conditioning may not be prepared for the heat.

“Make plans now for how you are going to stay cool,” Kittell said.

Temperatures will ebb slightly over the weekend, but it is not clear when the heat wave will subside.

However uncomfortable, the heat this week is not expected to break records. The record for the first week of September was set in 2020 when temperatures reached 121 in Woodland Hills.