Simi Valley, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

250
FXUS66 KLOX 201936
AFDLOX

Area Forecast Discussion...UPDATED
National Weather Service Los Angeles/Oxnard CA
1236 PM PDT Sun Jul 20 2025

.SYNOPSIS...20/226 AM.

Night through morning low clouds and fog will continue for most
coast and some valley locations through the week. There will be a
slight cooling trend to midweek, then warming for next weekend.

&&

.SHORT TERM (TDY-WED)...20/239 AM.

An area of low pressure aloft across the Pacific Northwest will
expand south through mid week and that will result in a cooling
trend, most notably across the interior areas where high
temperatures have been in the lower 100s but will drop into the
low to mid 90s most of the week with typical afternoon gusty winds.
For coast and coastal valleys the night and morning hours will be
filled with stratus that will clear off in most areas by early
afternoon, though some beaches may remain cloudy longer than that.
Highs will be 5-10 degrees below normal.

.LONG TERM (THU-SUN)...20/240 AM.

High confidence in quiet weather next week with limited if any
impacts. Starting Wednesday, daytimes highs are favored to creep
upwards each day, as a result of a slightly rising 500 mb heights
and weaker onshore flow. Highs are still favored to be near or
below normal through the upcoming weekend. Marine layer clouds
will continue, transported into the region by the overall onshore
surface pressure gradients.

By the end of the month, there is some indication in the long
range forecast models that above normal temperatures and heat may
build.

&&

.AVIATION...20/1935Z.

At 1833Z at KLAX, the marine layer was 2700 feet deep, with an
inversion top at 4400 feet and a maximum temperatures of 23 C.

High confidence in desert TAFs.

Moderate confidence in other TAF, with similar conditions
expected tonight and slow cloud clearing tomorrow. IFR to MVFR
conditions are expected to be widespread across the coast and
valleys, and flight categories may be one category lower at
times.

KLAX...Moderate confidence in TAF, arrival of cigs may be
off by +/- 2 hours this evening and heights off by +/- 300 ft.

KBUR...Moderate confidence in TAF, arrival of cigs may be
off by +/- 2 hours this evening and heights off by +/- 300 ft.

&&

.MARINE...20/1235 PM.

Overall, moderate to high confidence in the current forecast.
Higher confidence exists in the forecast for seas relative to
winds.

For the waters southwest through northwest of the Channel Islands
and beyond 10 NM offshore of the Central Coast, there is a
moderate-to-likely (50-60 percent) chance of Small Craft Advisory
(SCA) level winds developing each afternoon and evening evening
through Thursday evening. There will likely be a lull in winds during
the late night to early morning hours each day with winds
dropping below SCA levels. Increasing winds and building seas are
expected for late this week with a low-to-moderate (20-30
percent) chance of Gales from around Point Conception south to San
Nicolas Island.

For the nearshore waters along the Central Coast and north of
Point Sal, there is a moderate (30-40 percent) chance of SCA
level winds during the afternoon and evening hours through
Thursday evening, increasing to a high-to-likely (50-60 percent)
chance late this week.

Inside the southern California bight, there is a moderate-to-high
(30-50 percent) chance of SCA level winds each afternoon and
evening through Thursday, highest over the western portion of the
Santa Barbara Channel. The chance for SCA level winds will
increase to high-to-likely (50-70 percent) on Friday afternoon and
evening, and again on Saturday afternoon and evening.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
PZ...Small Craft Advisory in effect until 3 AM PDT Monday for
      zones 673-676. (See LAXMWWLOX).

&&

$$

PUBLIC...MW/Schoenfeld
AVIATION...Schoenfeld
MARINE...Hall
SYNOPSIS...MW/jld

weather.gov/losangeles

Experimental Graphical Hazardous Weather Outlook at:
https://www.weather.gov/erh/ghwo?wfo=lox