Santa Clara, California Weather
Ceanothus blooms again. Day 93 of summer. Read this microseason across nine climate regions →
Santa Clara weather forecast — hour by hour, 7-day outlook, NOAA radar
Conditions updated 7:25 AM PDT · Open-Meteo
- TodaySep 21Clear later——72°58°—
- TuesdaySep 22Mostly Clear——76°54°+4°
- WednesdaySep 23Clear——87°56°+11°
- ThursdaySep 24Overcast——88°64°+1°
- FridaySep 25Overcast——80°62°-8°
- SaturdaySep 26Overcast——87°62°+7°
- SundaySep 27Overcast——80°57°-7°
Air quality now AQI 50 · Good
AQI 50 (Good), driven by PM2.5. AQI flat over the last 6 hours (within ±3 points). PM2.5 at 8.6 µg/m³ (AQI 48) with a 0.77 fine-to-coarse ratio and 1 mph wind — combustion smoke trapped in stagnant 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
PM × Wind × Precip
PM2.5 at 8.6 µg/m³ (AQI 48) with a 0.77 fine-to-coarse ratio and 1 mph wind — combustion smoke trapped in stagnant air, not road dust.
- PM2.5/PM10
- 0.77
- 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).
September dries up ditches or breaks down bridges.
- Moonrise
- 4:36 PM
- Moonset
- 1:43 AM
- In sign
- ♑︎ Capricorn
Ceanothus blooms again
Read this microseason across nine climate regions →
All 72 microseasons on the year wheel →
Santa Clara at a glance
- Today vs. normal: Today averages 65°F (high 72°F, low 58°F), 3°F below the 68°F normal for Sep 21
- Last frost: January 12 (1991–2020 median, NOAA station 4 km away)
- Microseason: Sep 21–25
- Planting calendar: September — plant tomatoes, peppers, beans, squash; harvest tomatoes, peppers, beans, summer squash, winter squash
16-Day Forecast — Santa Clara
- Mon72°58°1%
- Tue76°54°1%
- Wed87°56°0%
- Thu88°64°0%
- Fri80°62°1%
- Sat87°62°0%
- Sun80°57°1%
- Mon84°60°1%
- Tue92°67°1%
- Wed95°70°3%
- Thu90°74°0%
- Fri94°77°6%
- Sat96°76°0%
- Sun96°74°0%
- Mon85°65°0%
- Tue84°61°0%
Forecast data from Open-Meteo (CC BY 4.0).
Live wind & temperature near Santa Clara
Interactive wind and temperature map centered on Santa Clara — it loads in your browser. Open the full weather map.
Right now in the garden
Peak growing season
As of September 21, the growing season is at its peak — the first frost (around December 22) is weeks away. Fall transplants go in about 10–12 weeks before the first frost, September 29 to October 13 here. This city's planting calendar for September: plant tomatoes, peppers, beans, and squash; harvest tomatoes, peppers, beans, summer squash, and winter squash.
Sun & seasons in Santa Clara
Santa Clara sits in Santa Clara County, where the year’s longest day runs 14h 44m of daylight and its shortest just 9h 35m — a swing of +5h 9m 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 300 miles to the SE. The nearest town Santa Clara tracks is Sunnyvale, roughly 3 miles to the WNW.
Air quality in Santa Clara
Air quality in Santa Clara’s county has trended cleaner since 2020; its cleanest year on record was 2023 (median AQI 43). See the full air-quality history for Santa Clara.
Planting calendar
| Month | Plant | Harvest |
|---|---|---|
| January | lettuce, peas, spinach, radishes | spinach, radishes, fall brassicas, carrots |
| February | — | lettuce, peas, spinach, radishes |
| March | — | lettuce, peas, spinach |
| April | tomatoes, peppers, beans, squash | lettuce, peas |
| May | tomatoes, peppers, beans, squash | garlic |
| June | beans, squash | beans, summer squash |
| July | beans, squash | tomatoes, peppers, beans, summer squash |
| August | tomatoes, peppers, beans, squash | tomatoes, peppers, beans, summer squash, winter squash |
| September | tomatoes, peppers, beans, squash | tomatoes, peppers, beans, summer squash, winter squash |
| October | beans, squash, fall brassicas, carrots | tomatoes, peppers, beans, summer squash, winter squash |
| November | garlic (overwinter) | tomatoes, peppers, beans, summer squash, winter squash |
| December | lettuce, peas, spinach, radishes, garlic (overwinter) | tomatoes, peppers, beans, summer squash, winter squash, fall brassicas, carrots |
A year in weather
August is Santa Clara's warmest stretch (~70°F) and December its coldest (~51°F); precipitation crests in January at 2.8 inches and ebbs in July to 0.0 inches.
| Month | Mean temp | Precip | Rainy days |
|---|---|---|---|
| January | 51° | 2.8″ | 9 |
| February | 53° | 2.7″ | 10 |
| March | 56° | 2.1″ | 9 |
| April | 59° | 1.1″ | 6 |
| May | 63° | 0.4″ | 3 |
| June | 67° | 0.2″ | 1 |
| July | 70° | 0.0″ | 0 |
| August | 70° | 0.1″ | 0 |
| September | 69° | 0.1″ | 1 |
| October | 64° | 0.5″ | 3 |
| November | 56° | 1.3″ | 7 |
| December | 51° | 2.3″ | 10 |
Regional context
Similar climates Sunnyvale, CA, Fruitdale, CA, Cupertino, CA
Santa Clara swings from 51°F in January to 70°F in July (19°F) per NOAA NCEI 1991-2020 normals; precipitation in Santa Clara runs about 13.5 inches on roughly 59 measurable days.
Santa Clara's moisture rides winter storm tracks: January brings 2.8 inches over 9.2 wet days, while July sees only 0.0 inches across 0.1 days in the dry warm season. It is a winter-storm rhythm Santa Clara shares with places like Sunnyvale, CA, Fruitdale, CA and Cupertino, CA.
Santa Clara reaches its last hard frost near January 12; that is the cue for lettuce, chard, arugula, and mustard greens. Tomatoes and peppers do best set out two weeks later in Santa Clara, once nights clear the mid-40s°F. By December 22, frost is back in Santa Clara — protect or harvest anything tender. That date is a median: Santa Clara freezes sooner in half of years.
Similar climates: Sunnyvale, CA, Fruitdale, CA, Cupertino, CA, Campbell, CA, Milpitas, CA.
Frequently asked
- When does it freeze in Santa Clara?
- Frost typically leaves Santa Clara by January 12 and returns to Santa Clara near December 22.
- What is the rainy season in Santa Clara?
- Rainfall in Santa Clara peaks in January near 2.8 inches, out of about 13 inches annually.
- What is the warmest month in Santa Clara?
- The warmest stretch in Santa Clara comes in August, around 70°F on average.
- What is the coldest month in Santa Clara?
- On average December is the chilliest month in Santa Clara, about 51°F.
- When can I start a vegetable garden in Santa Clara?
- Frost-hardy sowings begin at January 12 in Santa Clara; warm-season starts follow two weeks on.
- How many rainy days does Santa Clara get?
- Expect roughly 59 wet days a year in Santa Clara.
- What hardiness zone is Santa Clara?
- Santa Clara's hardiness zone tracks its winter low; with December near 51°F, check the USDA ZIP map for the exact zone.
- What is the 10-day forecast for Santa Clara?
- Santa Clara'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 Santa Clara?
- See this week's day-by-day rain chances for Santa Clara in the daily forecast above, and the next 24 hours in the hourly chart.
- What is the weather like right now in Santa Clara?
- Current conditions for Santa Clara and the next 24 hours — temperature, precipitation chance, and wind by the hour — are in the hourly forecast chart above.
- How often is the Santa Clara forecast updated?
- The Santa Clara forecast on this page is built from Open-Meteo weather-model data and refreshes regularly through the day.
- When are sunrise and sunset in Santa Clara?
- Today's sunrise and sunset times for Santa Clara 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 Santa Clara?
- The next few days in Santa Clara's forecast are the most reliable; accuracy declines beyond about a week as weather-model uncertainty grows.
Santa Clara sits at 37.4°N; its climate zone is hot-summer Mediterranean (Köppen approximation).
ZIP codes in Santa Clara
- 95050
- 95051
- 95052
- 95053
- 95054
- 95055
- 95056