Northern CA weather: High temperatures, mountain rainstorms

Portions of Northern California and the Central Valley are experiencing “extreme heat” through Tuesday, June 16, according to the National Weather Service. Temperatures in some areas are expected to climb well above 100 degrees, though a gradual cool down is forecast for mid-week with seasonable temperatures returning by the weekend.

Which regions are under heat advisories?

Heat advisories remain in effect through 11 p.m. Tuesday, June 16, for several major hubs including Sacramento, Modesto, Merced, and Fresno. The National Weather Service reports that “dangerous heat” continues to impact these cities and numerous surrounding foothill communities.

In the San Joaquin Valley, the National Weather Service expects high temperatures to reach up to 102 degrees. Fresno is forecast to peak around 101 degrees on Tuesday, while Merced may see highs nearing 98 degrees before cooling into the 80s by Thursday.

Did You Know? Redding is forecast to experience some of the region’s most intense conditions, with temperatures potentially reaching as high as 109 degrees.

What is the fire weather risk in the Sacramento Valley?

The National Weather Service stated that hot temperatures, low relative humidity, and breezy onshore winds will lead to “elevated fire weather conditions” through Tuesday. These conditions are specifically impacting the northern Sacramento Valley and adjacent terrain.

Other high-temperature forecasts for the northern valley include Red Bluff at 107 degrees and Chico at 104 degrees. These factors combine to create a high-risk environment for fire activity in the immediate term.

Expert Insight: Samantha Carter notes that the convergence of triple-digit heat and low humidity creates a volatile window for regional infrastructure. The transition from extreme heat to potential mountain thunderstorms may shift the primary risk from heat-stress to lightning-driven fire starts.

When will temperatures return to seasonable levels?

A gradual cool down is expected to begin mid-week. According to the National Weather Service, more seasonable temperatures are forecast to continue through the weekend starting Friday, June 19.

In Sacramento, highs are expected to stay near 93 to 95 degrees through Wednesday before falling below 90 degrees on Thursday. Modesto is forecast to see highs of 97 degrees on Monday and Tuesday, dropping to 95 degrees Wednesday and 93 degrees Thursday, eventually falling below 90 degrees by Friday.

What is the forecast for the Sierra Nevada mountains?

The Sierra Nevada may see an active weather system as valley temperatures ease. The National Weather Service is forecasting a chance of mountain showers and thunderstorms on Thursday, June 18, specifically in areas south of Highway 50.

Current forecasts indicate a 10% to 20% chance of precipitation in portions of the Sierra Nevada, including areas near Yosemite National Park and South Lake Tahoe. While widespread rainfall is not expected, these storms could bring gusty winds, lightning, and brief showers to small areas.

Frequently Asked Questions

How long will the extreme heat last in the Central Valley?
According to the National Weather Service, extreme heat will impact portions of the Central Valley and Northern California through Tuesday, June 16.

Which cities are currently under a heat advisory?
Sacramento, Modesto, Merced, and Fresno are under a heat advisory through 11 p.m. Tuesday.

Is there a chance of rain in the mountains?
Yes, there is a 10% to 20% chance of precipitation, including brief showers and thunderstorms, in portions of the Sierra Nevada on Thursday, June 18.

How does your local business or daily routine change when triple-digit temperatures hit your region?