The switch from summer to fall will not be a seamless transition, with another heat wave expected to grip the Inland Empire, the National Weather Service reported Wednesday.
“Temperatures for early next week will likely be around 10 degrees above average in the mountains and deserts, and 10 to 15 degrees above average for the coast and valleys,” the weather service said in a statement. “This will bring an extended period of moderate to occasionally high heat risk … Sunday to Wednesday.”
Forecasters said high pressure systems in the lower Great Plains states will influence weather patterns in the southwest United States, including Southern California, going into the weekend, ushering in clear, dry conditions.
The first day of fall is Thursday.
In the Riverside metropolitan area, temperatures will climb from the seasonable 80s of recent days to the upper-90s by Sunday and triple digits Monday and Tuesday, according to meteorologists. Lows will hover in the upper-60s over the next week.
In the Coachella Valley, triple-digit heat will begin Friday, and by early next week, highs will approach 110, the weather service said.
Nightly lows will be in the upper-70s and low-80s.
In the Temecula Valley, daytime highs will top out in the low-90s until Monday, when they are expected to rise into the upper 90s. Lows will be around 70 over the next seven days, forecasters said.
The region baked in the previous heat wave, which began at the end of August and continued through Labor Day weekend, with highs in the Riverside metropolitan area settling in the low-100s each day.