By admin 
Typically by mid-August, much of the Central Valley begins to see average temperatures begin to slowly tick down. For the lower Sacramento Valley and the Delta region, that means highs in the low to mid- 90s. For much of the San Joaquin Valley, including Fresno, mid-August average highs are still in the upper 90s.
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Instead, late last week we were treated to temperatures more typical of early October. Highs Friday topped out at a cool 79 degrees for Sacramento, 85 for Modesto, and only 91 for normally-scorching Fresno.
This week will not be a return to those cooler temps. With higher pressure setting in over the North Pacific Ocean and across the western U.S., our high temperatures will return to their rightful place in the 90s and even just over 100 degrees in Fresno.
On Monday, high temperatures are back to around 90 degrees for Sacramento, Stockton and much of the Delta region. These temps will rise slowly further both north and south as the effect of the Delta breeze minimizes: highs solidly in the 90s for Merced, Fresno and Redding.
Warmth trickles in through Tuesday and Wednesday, with Wednesday set to be the warmest day of the week for much of Central California before a return to average Monday-like temperatures by Friday. No heat advisories are expected at this time for the Central Valley, but intense heat Wednesday will be worth considering as you craft your plans for the week.
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It’s not all hot and sweaty though, as the Delta breeze is set to be a consistent feature all week long for Sacramento, Stockton, Modesto and much of the area in between. Winds gusting 20 mph or more after 5 p.m. will be a dependable factor in cooling down temperatures back into the 50s and 60s each evening and overnight.
Upper atmosphere will send passing clouds our way this week
The upper atmosphere is set to deliver Central California a consistent stream of passing clouds all week long. As a trough of lower pressure in the upper atmosphere sets up a growing ridge well offshore of California, a jet stream will develop in between this pressure gradient, bringing tropical moisture from the El Niño-warmed equator northward into the upper atmosphere across the Central Valley.
It is somehow true that Sacramento is the sunniest city on Earth in the month of August, but this week will not help the city keep its spot at No. 1 if the weather pattern keeps up. Clouds in the middle and upper layers of the atmosphere will be a consistent feature of the skies this week. That means lots of wispy cirrus clouds and thin altostratus clouds to add more color throughout the day — neither will block enough sunshine to call it a cloudy day, but it will be a welcome change of scenery.
Perhaps most exciting will be the possibility for spectacular sunrises and sunsets, as light from the sun bounces off the bottom of these elevated clouds in intense pink and orange colors.
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This story was originally published August 17, 2026 at 7:01 AM.