Stevenson Ranch, California Weather
Summer heat deepens across the valleys. Day 15 of summer. Read this microseason across nine climate regions →
Stevenson Ranch weather forecast — hour by hour, 7-day outlook, NOAA radar
- TodayJul 5Partly Cloudy——89°63°—
- MondayJul 6Clear——89°61°0°
- TuesdayJul 7Clear——92°64°+3°
- WednesdayJul 8Clear——98°65°+6°
- ThursdayJul 9Clear——99°66°+1°
- FridayJul 10Overcast——93°64°-6°
- SaturdayJul 11Overcast——93°64°0°
AQI 54 (Moderate), driven by PM2.5. AQI flat over the last 6 hours (within ±3 points). PM2.5 at 13.8 µg/m³ (AQI 60) with a 0.71 fine-to-coarse ratio and 3 mph wind — combustion smoke trapped in calm air, not road dust.
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 31 now. With UV 9.9 peaking around 1 PM under clear skies, surface ozone likely climbs to AQI 41 around 1 PM.
- Present
- AQI 31
- UV peak
- 9.9 at 1 PM
- Sky at peak
- clear
- Projected peak
- AQI 41
PM × Wind × Precip
PM2.5 at 13.8 µg/m³ (AQI 60) with a 0.71 fine-to-coarse ratio and 3 mph wind — combustion smoke trapped in calm air, not road dust.
- PM2.5/PM10
- 0.71
- Wind
- calm
- Recent rain
- 0h in last 6h
- Pattern
- stagnant smoke
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).
If the first of July be rainy weather, 'twill rain more or less for four weeks together.
- Moonrise
- 11:11 PM
- Moonset
- 11:13 AM
- In sign
- ♓︎ Pisces
Summer heat deepens across the valleys
Stevenson Ranch at a glance
- Today vs. normal: 6°F above the seasonal normal for this latitude
- Last frost: March 13 (climatological average for this latitude)
- Microseason: Jul 1–5
- Planting window: Harvest early potatoes. Begin drying onions on the surface.
ZIP code: 91381
16-Day Forecast — Stevenson Ranch
- Sun89°63°1%
- Mon89°61°0%
- Tue92°64°0%
- Wed98°65°0%
- Thu99°66°0%
- Fri93°64°0%
- Sat93°64°0%
- Sun97°66°1%
- Mon97°68°4%
- Tue96°72°6%
- Wed100°73°2%
- Thu100°74°10%
- Fri107°78°9%
- Sat115°83°6%
- Sun97°77°10%
- Mon98°72°10%
Forecast data from Open-Meteo (CC BY 4.0).
Right now in the garden
Peak growing season
As of July 5, the growing season is at its peak — frost is months away. Continue succession-planting beans and summer squash. Start fall brassicas (broccoli, cabbage, kale) from seed indoors for transplanting in late summer.
Microseason · July 1–5
Summer heat deepens across the valleys
Inland temperatures exceed 95°F regularly; fire danger reaches moderate to high across most of the region.
Day 186 of 365 · Wedge 37 of 72
Planting calendar
| Month | Plant | Harvest |
|---|---|---|
| January | — | — |
| February | — | — |
| March | lettuce, peas, spinach, radishes | — |
| April | lettuce, peas, spinach, radishes, tomatoes, peppers, beans, squash | — |
| May | tomatoes, peppers, beans, squash | lettuce, peas, radishes |
| June | tomatoes, peppers, beans, squash | lettuce, peas, radishes |
| July | — | tomatoes, beans, summer squash |
| August | — | tomatoes, beans, summer squash |
| September | — | tomatoes, beans, summer squash |
| October | fall brassicas, garlic (overwinter), carrots | winter squash, tomatoes (last) |
| November | fall brassicas, garlic (overwinter), carrots | — |
| December | — | — |
A year in weather
Stevenson Ranch peaks at about 80°F in August and bottoms near 53°F in December; February brings the heaviest rain (4.4 inches) and August the least (0.0 inches).
| Month | Mean temp | Precip | Rainy days |
|---|---|---|---|
| January | 55° | 4.2″ | 3 |
| February | 55° | 4.4″ | 5 |
| March | 59° | 2.9″ | 3 |
| April | 61° | 0.8″ | 2 |
| May | 67° | 0.3″ | 1 |
| June | 72° | 0.0″ | 0 |
| July | 79° | 0.0″ | 0 |
| August | 80° | 0.0″ | 0 |
| September | 77° | 0.1″ | 0 |
| October | 69° | 0.5″ | 1 |
| November | 60° | 0.8″ | 2 |
| December | 53° | 2.6″ | 3 |
Regional context
By the nearest station's NOAA NCEI 1991-2020 normals, Stevenson Ranch sees 55°F Januarys and 79°F Julys, a 24°F range, plus around 16.8 inches of precipitation across 19 days.
Precipitation in Stevenson Ranch peaks in the cool season: February averages 4.4 inches across 5.1 storm-fed days, while August bottoms out at 0.0 inches over just 0.0 rainy days. That cool-season-wet pattern aligns Stevenson Ranch with places like Santa Clarita, CA, Val Verde, CA and Castaic, CA.
Freezes are uncommon in Stevenson Ranch, where the coldest month averages 53°F; cool-season crops grow fall through spring. Summer heat in August (about 80°F) is the binding constraint, not cold. Across Stevenson Ranch, elevation and tree cover drive a 4-7°F spread in Stevenson Ranch's overnight lows.
Similar climates: Santa Clarita, CA, Val Verde, CA, Castaic, CA, Hasley Canyon, CA, Santa Susana, CA.
Frequently asked
- When does it freeze in Stevenson Ranch?
- In Stevenson Ranch, expect the last spring frost near mid-March; Stevenson Ranch's first autumn frost comes around mid-December.
- What is the rainy season in Stevenson Ranch?
- February is the wettest month in Stevenson Ranch, about 4.4 inches on average; the year totals roughly 17 inches.
- What is the warmest month in Stevenson Ranch?
- Stevenson Ranch peaks in August, when the mean runs near 80°F.
- What is the coldest month in Stevenson Ranch?
- December is Stevenson Ranch's coldest month, averaging about 53°F.
- When can I start a vegetable garden in Stevenson Ranch?
- In Stevenson Ranch, sow peas and hardy greens around mid-March; Stevenson Ranch's tomatoes and peppers wait two weeks more.
- How many rainy days does Stevenson Ranch get?
- Stevenson Ranch averages about 19 days with measurable rain or snow each year.
- What hardiness zone is Stevenson Ranch?
- Because Stevenson Ranch bottoms near 53°F in December, that winter low sets Stevenson Ranch's USDA zone — verify by ZIP.
- What is the 10-day forecast for Stevenson Ranch?
- Stevenson Ranch'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 Stevenson Ranch?
- See this week's day-by-day rain chances for Stevenson Ranch in the daily forecast above, and the next 24 hours in the hourly chart.
- What is the weather like right now in Stevenson Ranch?
- Current conditions for Stevenson Ranch and the next 24 hours — temperature, precipitation chance, and wind by the hour — are in the hourly forecast chart above.
- How often is the Stevenson Ranch forecast updated?
- The Stevenson Ranch forecast on this page is built from Open-Meteo weather-model data and refreshes regularly through the day.
- When are sunrise and sunset in Stevenson Ranch?
- Today's sunrise and sunset times for Stevenson Ranch 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 Stevenson Ranch?
- The next few days in Stevenson Ranch's forecast are the most reliable; accuracy declines beyond about a week as weather-model uncertainty grows.
Climate
The hot-summer Mediterranean climate of Stevenson Ranch, California carries typical Januarys near 55°F and Julys around 79°F — 24°F of seasonal travel.
In a typical year Stevenson Ranch records about 17 inches of precipitation on around 19 days.
Stevenson Ranch sits at 34.4°N; that 24°F seasonal swing frames planting windows and frost dates across Stevenson Ranch.
ZIP codes in Stevenson Ranch
- 91381