Simi Valley, California Weather
California lilac blooms in winter light. Day 50 of autumn. Read this microseason across nine climate regions →
Simi Valley weather forecast — hour by hour, 7-day outlook, NOAA radar
Conditions updated 1:29 PM PST · Open-Meteo
- TodayNov 10Clear——86°62°—
- WednesdayNov 11Clear——86°58°0°
- ThursdayNov 12Overcast23%—77°55°-9°
- FridayNov 13Drizzle54%—70°56°-7°
- SaturdayNov 14Showers54%0.30″66°54°-4°
- SundayNov 15Overcast25%—69°52°+3°
- MondayNov 16Light Drizzle43%0.04″64°50°-5°
Air quality now AQI 44 · Good
AQI 44 (Good), driven by Ozone. AQI flat over the last 6 hours (within ±3 points). Ozone at AQI 50 now. With UV 3.4 peaking around 1 PM under clear skies, surface ozone likely climbs to AQI 23.
OK No precautions needed for the general population; unusually sensitive individuals may consider limiting prolonged outdoor exertion.
What's driving it
Ozone × UV × Sky
Ozone at AQI 50 now. With UV 3.4 peaking around 1 PM under clear skies, surface ozone likely climbs to AQI 23.
- Present
- AQI 50
- UV peak
- 3.4 at 1 PM
- Sky at peak
- clear
- Projected peak
- AQI 23
Trends
Seven days of AQI and PM2.5.
Hourly air-quality data from the Copernicus Atmosphere Monitoring Service, charted across the past and next several days. Dashed lines mark the AQI breakpoints at 50 (Good → Moderate) and 100 (Moderate → Unhealthy for Sensitive Groups).
When the wind is in the west, the weather is at its best.
- Moonrise
- 8:00 AM
- Moonset
- 5:03 PM
- In sign
- ♐︎ Sagittarius
California lilac blooms in winter light
Read this microseason across nine climate regions →
All 72 microseasons on the year wheel →
Simi Valley at a glance
- Today vs. normal: Today averages 74°F (high 86°F, low 62°F), 12°F above the 62°F normal for Nov 10
- Last frost: January 24 (1991–2020 median, NOAA station 19 km away)
- Microseason: Nov 6–10
- Planting calendar: November — plant garlic (overwinter); harvest tomatoes, peppers, beans, summer squash, winter squash
16-Day Forecast — Simi Valley
- Tue86°62°0%
- Wed86°58°0%
- Thu77°55°23%
- Fri70°56°54%
- Sat66°54°54%
- Sun69°52°25%
- Mon64°50°43%
- Tue63°47°28%
- Wed66°47°31%
- Thu66°50°31%
- Fri65°54°17%
- Sat65°45°4%
- Sun71°46°16%
- Mon73°49°15%
- Tue71°50°10%
- Wed74°49°11%
Forecast data from Open-Meteo (CC BY 4.0).
Live wind & temperature near Simi Valley
Interactive wind and temperature map centered on Simi Valley — it loads in your browser. Open the full weather map.
Right now in the garden
Fall planting + final harvests
As of November 10, the season's first frost (typically December 15) is approaching. Pick what frost-tender plants still carry before the next cold front. This city's planting calendar for November: plant garlic (overwinter); harvest tomatoes, peppers, beans, summer squash, and winter squash.
Sun & seasons in Simi Valley
Simi Valley sits in Ventura County, where the year’s longest day runs 14h 27m of daylight and its shortest just 9h 52m — a swing of +4h 35m between the June and December solstices. Clocks spring forward on Sunday, March 8, 2026 and fall back on Sunday, November 1, 2026.
Los Angeles, the state’s largest city, lies about 22 miles to the ESE. The nearest town Simi Valley tracks is Thousand Oaks, roughly 9 miles to the SW.
Air quality in Simi Valley
Air quality in Simi Valley’s county has trended cleaner since 2020; its cleanest year on record was 2023 (median AQI 46). See the full air-quality history for Simi Valley.
Planting calendar
| Month | Plant | Harvest |
|---|---|---|
| January | lettuce, peas, spinach, radishes | radishes, fall brassicas, carrots |
| February | lettuce, peas, spinach, radishes | lettuce, spinach, radishes |
| March | tomatoes, peppers, beans, squash | lettuce, peas, spinach, radishes |
| April | tomatoes, peppers, beans, squash | lettuce, peas, spinach |
| May | beans, squash | beans, summer squash, garlic |
| June | beans, squash | tomatoes, peppers, beans, summer squash, winter squash |
| July | beans, squash | tomatoes, peppers, beans, summer squash, winter squash |
| August | tomatoes, peppers, beans, squash | tomatoes, peppers, beans, summer squash, winter squash |
| September | tomatoes, peppers, beans, squash, fall brassicas, carrots | tomatoes, peppers, beans, summer squash, winter squash |
| October | — | beans, summer squash, winter squash |
| November | garlic (overwinter) | tomatoes, peppers, beans, summer squash, winter squash |
| December | — | tomatoes, peppers, beans, summer squash, winter squash, fall brassicas, carrots |
A year in weather
August is Simi Valley's warmest stretch (~79°F) and December its coldest (~56°F); precipitation crests in February at 4.6 inches and ebbs in August to 0.0 inches.
| Month | Mean temp | Precip | Rainy days |
|---|---|---|---|
| January | 56° | 3.7″ | 6 |
| February | 57° | 4.6″ | 7 |
| March | 60° | 2.7″ | 6 |
| April | 63° | 0.8″ | 2 |
| May | 67° | 0.4″ | 2 |
| June | 73° | 0.1″ | 0 |
| July | 78° | 0.0″ | 0 |
| August | 79° | 0.0″ | 0 |
| September | 76° | 0.1″ | 1 |
| October | 69° | 0.6″ | 2 |
| November | 61° | 0.8″ | 3 |
| December | 56° | 2.7″ | 6 |
Regional context
Similar climates Santa Susana, CA, Bell Canyon, CA, Oak Park, CA
Simi Valley's climate, from NOAA NCEI 1991-2020 station normals, pairs 56°F Januarys with 78°F Julys — a 22°F swing. About 16.4 inches of precipitation falls over roughly 35 days a year.
Simi Valley's moisture rides winter storm tracks: February brings 4.6 inches over 6.8 wet days, while August sees only 0.0 inches across 0.2 days in the dry warm season. That cool-season-wet pattern aligns Simi Valley with places like Santa Susana, CA, Bell Canyon, CA and Oak Park, CA.
Simi Valley's growing window opens around January 24, once Simi Valley's overnight lows stop freezing — sow lettuce, chard, arugula, and mustard greens. In Simi Valley, warm-season transplants — tomatoes, peppers, basil — wait two weeks past Simi Valley's frost date. It shuts near December 15, when freezes return to Simi Valley and tender plants need cover. Sheltered Simi Valley yards can escape a light frost.
Similar climates: Santa Susana, CA, Bell Canyon, CA, Oak Park, CA, Moorpark, CA, Agoura Hills, CA.
Frequently asked
- When does it freeze in Simi Valley?
- Simi Valley's last spring frost lands near January 24, and in Simi Valley the first fall frost follows around December 15.
- What is the rainy season in Simi Valley?
- Rainfall in Simi Valley peaks in February near 4.6 inches, out of about 16 inches annually.
- What is the warmest month in Simi Valley?
- On average August tops the year in Simi Valley at about 79°F.
- What is the coldest month in Simi Valley?
- The coldest stretch in Simi Valley falls in December, around 56°F on average.
- When can I start a vegetable garden in Simi Valley?
- Hardy spring crops go in near January 24 in Simi Valley; tender peppers and squash wait 10–14 days.
- How many rainy days does Simi Valley get?
- Expect roughly 35 wet days a year in Simi Valley.
- What hardiness zone is Simi Valley?
- With December around 56°F, Simi Valley's zone reflects that minimum — the USDA ZIP map confirms Simi Valley's band.
- What is the 10-day forecast for Simi Valley?
- Simi Valley's extended outlook — daily high and low temperatures and precipitation chances for each upcoming day — is in the daily forecast above.
- Will it rain this week in Simi Valley?
- See this week's day-by-day rain chances for Simi Valley in the daily forecast above, and the next 24 hours in the hourly chart.
- What is the weather like right now in Simi Valley?
- Current conditions for Simi Valley and the next 24 hours — temperature, precipitation chance, and wind by the hour — are in the hourly forecast chart above.
- How often is the Simi Valley forecast updated?
- The Simi Valley forecast on this page is built from Open-Meteo weather-model data and refreshes regularly through the day.
- When are sunrise and sunset in Simi Valley?
- Today's sunrise and sunset times for Simi Valley are in the Almanac section above, along with civil dawn, civil dusk, and day length. Day length is longest near the summer solstice and shortest near the winter solstice.
- How accurate is the weather forecast for Simi Valley?
- The next few days in Simi Valley's forecast are the most reliable; accuracy declines beyond about a week as weather-model uncertainty grows.
Simi Valley sits at 34.3°N; its climate zone is hot-summer Mediterranean (Köppen approximation).
ZIP codes in Simi Valley
- 93062
- 93063
- 93065
- 93094
- 93099