BAKERSFIELD, Calif. (KGET) — Temperatures were a little less hot on Sunday due to an upper low just off the central California coast. Highs in the San Joaquin Valley were generally two to four degrees above climatological average for late August.

The high temperature at Fresno and Bakersfield was 98 degrees, ending a 16-day stretch of triple digit highs at Fresno and a 14-day stretch at Bakersfield.

The upper low off the coast will slowly drift north Monday across the San Francisco Bay area. Little changes in temperatures are expected with highs mainly in the middle to upper 90s across the San Joaquin Valley. The low then weakens into an open wave and accelerates northward on Tuesday as an upper high strengthens over the Desert Southwest.

Model ensemble means strengthen the ridge through the end of the week as it becomes centered over the Great Basin and extends west across California. By Sunday or Monday, the ridge becomes centered over California. Temperatures will begin trending hotter Tuesday with widespread triple digit heat returning to the San Joaquin Valley on Wednesday.

Further warming will raise high temperatures to around 10 to 12 degrees above average on Thursday and Friday. A bit more warming is forecast this weekend as the upper high moves overhead.

Highs next Sunday and Monday are forecast to be around 15 degrees above average for early September. These temperatures will bring an increasing risk for heat related illnesses to lower elevations.

A high heat risk develops across the desert areas Wednesday with a widespread moderate heat risk for the rest of the low elevations. The high heat risk area expands in coverage Thursday through the weekend with some areas becoming very high heat risk.

An Excessive Heat Watch has been issued for the lower elevations including the San Joaquin Valley, Coastal Range, lower Sierra Nevada Foothills, Yosemite Valley, Kern River Valley, Mojave Desert and Slopes, and the Indian Wells Valley from late Wednesday morning through Monday evening.

There is potential for reaching a record high temperature in Fresno on Thursday as the forecast is 106 degrees with a record of 107. More record highs may be reached next Sunday and Monday as the heat increases to possibly the hottest temperatures this year.