Stevenson Ranch, California Weather
Coastal fog thickens at dawn. Day 78 of spring. Read this microseason across nine climate regions →
Stevenson Ranch weather forecast — hour by hour, 7-day outlook, NOAA radar
- TodayJun 4Clear——90°61°—
- FridayJun 5Clear——89°55°-1°
- SaturdayJun 6Overcast——80°54°-9°
- SundayJun 7Clear——80°53°0°
- MondayJun 8Overcast——79°53°-1°
- TuesdayJun 9Overcast——73°57°-6°
- WednesdayJun 10Clear——85°52°+12°
AQI 129 (Unhealthy for Sensitive Groups), driven by Ozone. AQI up 69 in the last 6 hours — air quality is degrading. Ozone at AQI 86 now. With UV 0.0 peaking around 1 PM under clear skies, surface ozone likely climbs to AQI 21 by mid-afternoon.
CAUTION Sensitive groups (children, elderly, respiratory conditions) should limit prolonged outdoor exertion.
What's driving it
Ozone × UV × Sky
Ozone at AQI 86 now. With UV 0.0 peaking around 1 PM under clear skies, surface ozone likely climbs to AQI 21 by mid-afternoon.
- Present
- AQI 86
- UV peak
- 0.0 at 1 PM
- Sky at peak
- clear
- Projected peak
- AQI 21
PM × Wind × Precip
PM2.5 at 19.3 µg/m³, PM10 at 33.8 µg/m³ — typical background levels with no transport signature.
- PM2.5/PM10
- 0.57
- Wind
- calm
- Recent rain
- 0h in last 6h
- Pattern
- background
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).
The higher the clouds, the finer the weather.
- Moonrise
- 6:44 AM
- Moonset
- 5:18 PM
- In sign
- ♒︎ Aquarius
Coastal fog thickens at dawn
Stevenson Ranch at a glance
- Today vs. normal: 7°F below the seasonal normal for this latitude
- Last frost: March 13 (climatological average for this latitude)
- Microseason: Jun 1–5
- Planting window: Harvest spring lettuce before it bolts. Sow heat-tolerant greens.
Right now in the garden
Peak growing season
As of June 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.
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's warmest month is August (~80°F mean) and its coldest is December (~53°F). Rainfall peaks in February (4.4 inches) and bottoms out in August (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
Stevenson Ranch sits within a hot-summer Mediterranean climate region — a cohort that shares similar temperature ranges, seasonal patterns, and growing conditions across nearby cities.
Similar climates: Los Angeles, CA, San Francisco, CA, San Diego, CA, Riverside, CA, Sacramento, CA.
Frequently asked
- When does it freeze in Stevenson Ranch?
- Stevenson Ranch's last spring frost typically falls around mid-March, and the first fall frost arrives around mid-December.
- What is the rainy season in Stevenson Ranch?
- February is the wettest month with about 4.4 inches of rain on average; the city receives roughly 17 inches annually.
- What is the warmest month in Stevenson Ranch?
- August is typically warmest, averaging about 80°F.
- What is the coldest month in Stevenson Ranch?
- December is typically coldest, averaging about 53°F.
- When can I start a vegetable garden in Stevenson Ranch?
- Cool-season crops (peas, lettuce) can be sown around the last spring frost (mid-March); warm-season crops (tomatoes, peppers) wait until 1–2 weeks after.
- How many rainy days does Stevenson Ranch get?
- Stevenson Ranch averages about 19 rainy days per year.
- What hardiness zone is Stevenson Ranch?
- Stevenson Ranch's USDA hardiness zone is determined by its lowest average winter temperature; check the USDA's online lookup with the city ZIP for the current zone designation.
Climate
Stevenson Ranch, California sits in a hot-summer Mediterranean climate zone. January means hover near 55°F while July averages 79°F — a 24°F seasonal swing.
Across the year, Stevenson Ranch receives about 17 inches of precipitation spread over roughly 19 rainy days.
The rhythm of the year is set by latitude (34.4°N), proximity to large water bodies, and elevation — all of which shape what grows here, when frost is likely, and what the weather story looks like day to day.