Challenge, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

226
FXUS66 KSTO 141846
AFDSTO

Area Forecast Discussion
National Weather Service Sacramento CA
1146 AM PDT Sun Jun 14 2026

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


.KEY MESSAGES...

 - Hot, well-above average temperatures through Tuesday with
   widespread Moderate HeatRisk and areas of Major HeatRisk in the
   northern/central Sac Valley. Hottest temperatures on Monday.

 - Chances for mountain showers/thunderstorms today south of US 50
   and along the Sierra crest on Thursday.

 - Cooler temperatures Thursday into the weekend with increased
   Delta breeze.
&&

.DISCUSSION...

Hot, well-above normal temperatures continue today with
widespread Moderate HeatRisk and areas of Major HeatRisk in the
northern/central Sacramento Valley and adjacent foothills. Hottest
temperatures of the week are expected on Monday, with highs
approaching 110 in the northern Sacramento Valley. Expect elevated
overnight lows in the upper 60s to mid 70s as well which will
limit overnight relief. As a result, an Extreme Heat Warning is in
effect through 11 PM Tuesday. Diurnal delta breeze influence will
work to keep the vicinity Delta and Sacramento area cooler
compared to the rest of the Valley through this heat event, but
highs will still be in the mid to upper 90s. Remember to stay cool
and hydrated, and consider checking in on those more sensitive to
heat.

These hot temperatures combined with low relative humidity and
breezy onshore winds, will lead to elevated fire weather
conditions in the northern Sacramento Valley and adjacent terrain
through Tuesday. Daytime RHs will be in the teens to mid 20s, with
overnight recoveries in the 50s. A few areas may see single digit
RHs as well.

Temperatures begin a gradual cooling trend Wednesday onward as
ridging overhead breaks down. More significant cooling expected
Thursday into the weekend, with increased onshore flow through
the Delta and Valley and below-normal high temperatures.

Dry weather is expected over the next 7 days, however there
remains a 10-20% chance for isolated showers/thunderstorms over
the Sierra crest today south of US 50 and Thursday.

&&

.AVIATION...

VFR conditions with clear skies over the next 24 hours. Winds
generally less than 12 kts everywhere, except in the immediate vicinity
of the Delta, where westerly gusts up to 25 kts are possible
through the forecast period.

&&

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

&&

$$