If you feel like you’ve got a case of weather whiplash, you’re not alone. In less than a week, high temperatures in the Fresno area will take a 20-degree jump upward into triple-digit territory.

From Monday’s high of 85, temperatures will gradually climb this week until Friday, when the edge of a high-pressure system that’s cooking the rest of the U.S. will move over Fresno, raising Saturday’s forecast high to 105, National Weather Service meteorologist Brian Ochs said Tuesday.

The relatively cooler high temperatures last weekend and Monday were due to a low-pressure system from the Pacific Northwest that worked like a big air-conditioner over the region, Ochs said.

Monday’s high was about seven degrees cooler than the average high for June 17, and more than 10 degrees cooler than June 17 last year, according to National Weather Service records.

The highs this week will gradually creep upward, with a high for Tuesday forecast at 90 degrees, 91 on Juneteenth, 94 on Thursday, and 99 on Friday.

This presents the possible worst case scenario. For example, there is a 25% Probability of a High Temperature of 106F or greater at Fresno on Sunday. #CAwx #heatwave pic.twitter.com/SnZlUZgfa4

— NWS Hanford (@NWSHanford) June 18, 2024

A Hot Weekend

Triple-digit high temperatures are forecast to continue Saturday until midweek next week, when a new low from the Pacific Northwest could cause a cool-off starting Thursday, Ochs said.

“It’s not too unusual to see triple digits, especially as we’re getting into the later part of June,” he said. “But we’re still going to be probably about 10 degrees above average though, especially if we’re looking at 105 degrees on Saturday.”

And, depending on what part of Fresno you’re in, it could be hotter, Ochs said.

The good news about the upcoming heat wave is that no precipitation is forecast for the Sierra, so there shouldn’t be any lightning strikes to spark wildfires, he said.

A Hot Summer

But if you’re planning further out, the Fourth of July has a good chance of being back in the triple-digit high temperatures, and later in July there’s a 40% chance of above-average high temperatures, Ochs said.

The hottest part of the summer is from about July 20 to Aug. 7, when the average high is 98 degrees, Ochs said. With a forecast of above-average temperatures for those weeks this year, more triple-digit weather is likely, he said.