Thermalito, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

121
FXUS66 KSTO 221943
AFDSTO

Area Forecast Discussion
National Weather Service Sacramento CA
1243 PM PDT Sun Jun 22 2025

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

.DISCUSSION...

.SYNOPSIS...

Breezy and relatively cool weather continues today before a
return to near normal temperatures and onshore flow this week.
Mountain showers and isolated thunderstorms expected for Monday PM
but dry conditions otherwise throughout the week. &&

.KEY MESSAGES...

* Today:

 -Fire weather impacts trend lower today with elevated fire
  weather concerns lingering over the Northern Sacramento Valley
  and Northern San Joaquin Valley for low humidity and breezy
  winds.
  --Min RHs in upper teens to 20s this afternoon and gusts up to
    15-25 MPH

 -Seasonably cool temperatures expected, with Valley high
  temperatures in the 80s and 60s to 70s at higher elevations.

 -Please continue to practice fire safety such as, properly
  extinguishing any campfires, not driving over dry grass,
  checking your vehicle for chains or hanging objects that may
  cause sparks.

* The Week Ahead:

 -Gradual warming trend through midweek with temperatures
  returning to seasonal normal values. Valley high temperatures in
  the 90s with 70s to 80s expected at higher elevations.

 -Slight (10-20%) chance of isolated mountain thunderstorms Monday
  PM from Highway 50 southward.

 -Primarily dry weather then expected to follow as periodically
  breezy onshore flow develops late Monday-Tuesday.
--Monday`s Min RH over the N. Sacramento Valley: 10-15%

 -Some uncertainty in upper level pattern late in the week, but
  current ensemble trends indicate further warming with areas of
  Moderate HeatRisk and triple digit highs (N. Sac Valley)
  potentially returning by next weekend.

.Changes from previous forecast...
 -No changes from the previous forecast.

&&

.AVIATION...


VFR conditions persist at TAF sites next 24 hours. North to west
winds remain breezy, but generally 12 kts or less. Isolated
mountain shower/thunderstorm chances after 21z from Interstate 80
southward.
&&

.STO WATCHES/WARNINGS/ADVISORIES...
None.
&&

$$