Alta Sierra, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

637
FXUS66 KSTO 131924
AFDSTO

Area Forecast Discussion
National Weather Service Sacramento CA
1224 PM PDT Sat Jun 13 2026

For additional details on weather and expected impacts over the
next 7 days, please visit weather.gov/sto/briefing.



.KEY MESSAGES...

 - Well above normal temps in the lower elevations, triple digit
   highs with widespread Moderate HeatRisk/Areas of Major HeatRisk
   into the weekend (outside of the vicinity Delta).

 - Significant warm-up Sunday-Tuesday with Widespread Major
   HeatRisk for the northern and central Sacramento Valley.
   Widespread Moderate HeatRisk elsewhere.

 - Hottest temperatures on Monday for the area north of I-80,
   with areas of Major HeatRisk.

&&

.DISCUSSION...

Triple digit or near-triple digit Valley highs are expected this
afternoon with the exception of the Delta vicinity locations.
Widespread Moderate HeatRisk remains in place this afternoon,
with areas of Major HeatRisk across the northern Sacramento
Valley and adjacent foothills. Delta breeze influenced locations
will see some cooling through the weekend. The Heat Advisory
continues for the northern and central Sacramento Valley and
adjacent foothills through 11 pm tonight. While other areas in the
Valley will benefit from the Delta breeze cooling influence,
especially in the evening, it remains important for everyone in
interior NorCal to practice heat safety! Stay cool and hydrated,
and consider checking in on those more sensitive to heat.

High temperatures continue to trend higher for the northern and
central Sacramento Valley Sunday-Tuesday, with up to 110 in the
northern Sacramento Valley along with overnight lows in the upper
60s to mid 70s. An Extreme Heat Warning remains in effect for the
northern Sacramento Valley, adjacent mountains and foothills, and
Butte County from 11 am Sunday to 11 pm Tuesday. Temperatures are
forecast to trend lower mid to late week, back to near normal
Thursday and Friday.

Mainly dry weather is expected into next week. A few stray
showers or an isolated thunderstorm are possible over the Sierra
crest south of US HWY 50 this weekend into Monday, with more
widespread chances over the mountains mid to late week.

&&

.AVIATION...
VFR conditions with clear skies over the next 24 hours. Winds
generally less than 12 kts everywhere this afternoon, except in
the vicinity of the Delta, where westerly gusts up to 25 kts
remain until around 14z Sunday.

&&


.STO WATCHES/WARNINGS/ADVISORIES...
Heat Advisory until 11 PM PDT this evening for Butte County
Below 1000 ft-Central Colusa County Incl. I-5-Central Glenn Co &
Interstate 5-Eastern Colusa County-Eastern Glenn County-N. Sac
Valley in Tehama County-Shasta Metro-Sierra (Tehama-Plumas) 1000-
3000 ft-Sutter/Yuba counties below 1000 ft-W Tehama Co Foothills
1000-3000 ft-W. Glenn/Colusa Foothills 1000-3000 ft-W. Shasta
County 1000-3000 ft.

&&

$$