San Bernardino, California Weather
Ceanothus blooms again. Day 93 of summer. Read this microseason across nine climate regions →
San Bernardino weather forecast — hour by hour, 7-day outlook, NOAA radar
Conditions updated 7:26 AM PDT · Open-Meteo
- TodaySep 21Clear later——82°62°—
- TuesdaySep 22Overcast——84°64°+2°
- WednesdaySep 23Foggy——94°61°+10°
- ThursdaySep 24Clear——94°78°0°
- FridaySep 25Overcast——94°76°0°
- SaturdaySep 26Overcast——94°78°0°
- SundaySep 27Overcast——89°77°-5°
Air quality now AQI 59 · Moderate
AQI 59 (Moderate), driven by PM2.5. AQI flat over the last 6 hours (within ±3 points). PM2.5 at 21.6 µg/m³ (AQI 74) with a 0.94 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 21.6 µg/m³ (AQI 74) with a 0.94 fine-to-coarse ratio and 1 mph wind — combustion smoke trapped in stagnant air, not road dust.
- PM2.5/PM10
- 0.94
- 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
- 4:08 PM
- Moonset
- 1:32 AM
- In sign
- ♑︎ Capricorn
Ceanothus blooms again
Read this microseason across nine climate regions →
All 72 microseasons on the year wheel →
San Bernardino at a glance
- Today vs. normal: Today averages 72°F (high 82°F, low 62°F), about the 73°F normal for Sep 21
- Last frost: January 27 (1991–2020 median, NOAA station 15 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 — San Bernardino
- Mon82°62°3%
- Tue84°64°1%
- Wed94°61°0%
- Thu94°78°2%
- Fri94°76°3%
- Sat94°78°1%
- Sun89°77°3%
- Mon97°73°6%
- Tue99°78°8%
- Wed101°82°7%
- Thu103°85°6%
- Fri103°87°11%
- Sat101°84°13%
- Sun100°85°12%
- Mon98°84°10%
- Tue93°81°6%
Forecast data from Open-Meteo (CC BY 4.0).
Live wind & temperature near San Bernardino
Interactive wind and temperature map centered on San Bernardino — 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 19) is weeks away. Fall transplants go in about 10–12 weeks before the first frost, September 26 to October 10 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 San Bernardino
San Bernardino sits in San Bernardino County, where the year’s longest day runs 14h 26m of daylight and its shortest just 9h 52m — a swing of +4h 34m 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 64 miles to the W. The nearest town San Bernardino tracks is Fontana, roughly 10 miles to the WSW.
Air quality in San Bernardino
Air quality in San Bernardino’s county has trended cleaner since 2020; its cleanest year on record was 2023 (median AQI 71). See the full air-quality history for San Bernardino.
Planting calendar
| Month | Plant | Harvest |
|---|---|---|
| January | lettuce, peas, spinach, radishes | radishes, fall brassicas, carrots |
| February | lettuce, peas, spinach, radishes | lettuce, spinach, radishes |
| March | — | lettuce, peas, spinach, radishes |
| April | tomatoes, peppers, beans, squash | lettuce, peas, spinach |
| 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 | — | tomatoes, peppers, beans, summer squash, winter squash, fall brassicas, carrots |
A year in weather
San Bernardino peaks at about 79°F in August and bottoms near 49°F in December; February brings the heaviest rain (2.0 inches) and June the least (0.0 inches).
| Month | Mean temp | Precip |
|---|---|---|
| January | 49° | 1.9″ |
| February | 51° | 2.0″ |
| March | 53° | 1.8″ |
| April | 59° | 0.9″ |
| May | 66° | 0.3″ |
| June | 72° | 0.0″ |
| July | 79° | 0.4″ |
| August | 79° | 0.3″ |
| September | 75° | 0.2″ |
| October | 67° | 0.4″ |
| November | 56° | 0.9″ |
| December | 49° | 1.6″ |
Regional context
Similar climates Muscoy, CA, Rialto, CA, Colton, CA
In San Bernardino, modelled 1991-2020 normals (EC_Earth3P_HR model via Open-Meteo) put January near 49°F and July near 79°F — a 30°F seasonal arc — with about 10.9 inches of precipitation.
San Bernardino's moisture rides winter storm tracks: February brings 2.0 inches, while June sees only 0.0 inches in the dry warm season. That cool-season-wet pattern aligns San Bernardino with places like Muscoy, CA, Rialto, CA and Colton, CA.
San Bernardino reaches its last hard frost near January 27; that is the cue for lettuce, chard, arugula, and mustard greens. Tomatoes and peppers do best set out two weeks later in San Bernardino, once nights clear the mid-40s°F. Frost returns to San Bernardino near December 19, ending the tender-crop season. Open lawns in San Bernardino whiten first when frost returns.
Similar climates: Muscoy, CA, Rialto, CA, Colton, CA, Loma Linda, CA, Crestline, CA.
Frequently asked
- When does it freeze in San Bernardino?
- San Bernardino's last spring frost lands near January 27, and in San Bernardino the first fall frost follows around December 19.
- What is the rainy season in San Bernardino?
- February is the wettest month in San Bernardino, about 2.0 inches on average; the year totals roughly 11 inches.
- What is the warmest month in San Bernardino?
- August is San Bernardino's warmest month, averaging about 79°F.
- What is the coldest month in San Bernardino?
- San Bernardino bottoms out in December, with a mean near 49°F.
- When can I start a vegetable garden in San Bernardino?
- Frost-hardy sowings begin at January 27 in San Bernardino; warm-season starts follow two weeks on.
- What hardiness zone is San Bernardino?
- San Bernardino sits in the USDA zone set by December lows near 49°F; the USDA ZIP tool gives the band.
- What is the 10-day forecast for San Bernardino?
- San Bernardino'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 San Bernardino?
- See this week's day-by-day rain chances for San Bernardino in the daily forecast above, and the next 24 hours in the hourly chart.
- What is the weather like right now in San Bernardino?
- Current conditions for San Bernardino and the next 24 hours — temperature, precipitation chance, and wind by the hour — are in the hourly forecast chart above.
- How often is the San Bernardino forecast updated?
- The San Bernardino forecast on this page is built from Open-Meteo weather-model data and refreshes regularly through the day.
- When are sunrise and sunset in San Bernardino?
- Today's sunrise and sunset times for San Bernardino 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 San Bernardino?
- The next few days in San Bernardino's forecast are the most reliable; accuracy declines beyond about a week as weather-model uncertainty grows.
San Bernardino sits at 34.1°N; its climate zone is hot-summer Mediterranean (Köppen approximation).
ZIP codes in San Bernardino
- 92346
- 92369
- 92401
- 92403
- 92404
- 92405
- 92406
- 92407
- 92408
- 92410
- 92411
- 92413
- 92415
- 92418
- 92423
- 92427