Fontana, California Weather
Ceanothus blooms again. Day 93 of summer. Read this microseason across nine climate regions →
Fontana weather forecast — hour by hour, 7-day outlook, NOAA radar
Conditions updated 1:39 AM PDT · Open-Meteo
- TodaySep 21Overcast later——81°63°—
- TuesdaySep 22Mostly Clear——83°61°+2°
- WednesdaySep 23Clear——93°74°+10°
- ThursdaySep 24Clear——94°77°+1°
- FridaySep 25Overcast——95°76°+1°
- SaturdaySep 26Overcast——95°79°0°
- SundaySep 27Overcast——93°79°-2°
Air quality now AQI 64 · Moderate
AQI 64 (Moderate), driven by PM2.5. AQI flat over the last 6 hours (within ±3 points). PM2.5 at 15.4 µg/m³ (AQI 63) with a 0.84 fine-to-coarse ratio and 2 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 15.4 µg/m³ (AQI 63) with a 0.84 fine-to-coarse ratio and 2 mph wind — combustion smoke trapped in stagnant air, not road dust.
- PM2.5/PM10
- 0.84
- 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
- 4:09 PM
- Moonset
- 1:33 AM
- In sign
- ♑︎ Capricorn
Ceanothus blooms again
Read this microseason across nine climate regions →
All 72 microseasons on the year wheel →
Fontana at a glance
- Today vs. normal: Today averages 72°F (high 81°F, low 63°F), 3°F below the 75°F normal for Sep 21
- Last frost: None in most years — 32°F in 41% of 1991–2020 years (NOAA station 14 km away)
- Microseason: Sep 21–25
- Planting calendar: September — plant lettuce, peas, spinach, radishes, beans, squash; harvest lettuce, peas, spinach, radishes, tomatoes, peppers, beans, summer squash, winter squash
15-Day Forecast — Fontana
- Mon81°63°1%
- Tue83°61°0%
- Wed93°74°0%
- Thu94°77°3%
- Fri95°76°1%
- Sat95°79°1%
- Sun93°79°4%
- Mon99°81°9%
- Tue101°86°15%
- Wed89°74°13%
- Thu74°68°3%
- Fri92°72°6%
- Sat93°78°13%
- Sun99°80°12%
- Mon86°72°3%
Forecast data from Open-Meteo (CC BY 4.0).
Live wind & temperature near Fontana
Interactive wind and temperature map centered on Fontana — it loads in your browser. Open the full weather map.
Right now in the garden
Year-round growing
As of September 21, sowing here runs through the year. Freezes are uncommon, so there is no frost date to plan around; heat and rainfall set the calendar instead. This city's planting calendar for September: plant lettuce, peas, spinach, radishes, beans, and squash; harvest lettuce, peas, spinach, radishes, tomatoes, peppers, beans, summer squash, and winter squash.
Sun & seasons in Fontana
Fontana sits in San Bernardino County, where the year’s longest day runs 14h 26m of daylight and its shortest just 9h 53m — a swing of +4h 33m 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 54 miles to the W. The nearest town Fontana tracks is Rancho Cucamonga, roughly 6 miles to the WNW.
Air quality in Fontana
Air quality in Fontana’s county has trended cleaner since 2020; its cleanest year on record was 2023 (median AQI 71). See the full air-quality history for Fontana.
Planting calendar
| Month | Plant | Harvest |
|---|---|---|
| January | lettuce, peas, spinach, radishes | lettuce, peas, spinach, radishes |
| February | lettuce, peas, spinach, radishes | lettuce, peas, spinach, radishes |
| March | lettuce, peas, spinach, radishes | lettuce, peas, spinach, radishes |
| April | lettuce, peas, spinach, radishes, tomatoes, peppers, beans, squash | lettuce, peas, spinach, radishes |
| May | spinach, radishes, tomatoes, peppers, beans, squash | lettuce, peas, spinach, radishes, summer squash |
| June | tomatoes, peppers, beans, squash | lettuce, peas, spinach, radishes, tomatoes, peppers, beans, summer squash |
| July | lettuce, peas, tomatoes, peppers, beans, squash | tomatoes, peppers, beans, summer squash, winter squash |
| August | lettuce, peas, spinach, radishes, tomatoes, peppers, beans, squash | tomatoes, peppers, beans, summer squash, winter squash |
| September | lettuce, peas, spinach, radishes, beans, squash | lettuce, peas, spinach, radishes, tomatoes, peppers, beans, summer squash, winter squash |
| October | lettuce, peas, spinach, radishes | lettuce, peas, spinach, radishes, tomatoes, peppers, beans, summer squash, winter squash |
| November | lettuce, peas, spinach, radishes | lettuce, peas, spinach, radishes, tomatoes, peppers, beans, summer squash, winter squash |
| December | lettuce, peas, spinach, radishes | lettuce, peas, spinach, radishes |
A year in weather
In Fontana, August runs warmest near 80°F and January coldest around 52°F, while February is the wettest month (3.4 inches) and August the driest (0.0 inches).
| Month | Mean temp | Precip |
|---|---|---|
| January | 52° | 3.3″ |
| February | 54° | 3.4″ |
| March | 57° | 3.0″ |
| April | 62° | 1.5″ |
| May | 67° | 0.5″ |
| June | 73° | 0.1″ |
| July | 79° | 0.1″ |
| August | 80° | 0.0″ |
| September | 76° | 0.1″ |
| October | 69° | 0.5″ |
| November | 59° | 1.6″ |
| December | 53° | 2.6″ |
Regional context
Similar climates Bloomington, CA, Rialto, CA, Rancho Cucamonga, CA
Fontana's climate, from modelled 1991-2020 normals (EC_Earth3P_HR model via Open-Meteo), pairs 52°F Januarys with 79°F Julys — a 27°F swing. About 16.7 inches of precipitation falls each year.
Fontana's moisture rides winter storm tracks: February brings 3.4 inches, while August sees only 0.0 inches in the dry warm season. That cool-season-wet pattern aligns Fontana with places like Bloomington, CA, Rialto, CA and Rancho Cucamonga, CA.
Fontana rarely sees a hard freeze — its coldest month sits near 52°F — so planting spans most of the calendar. Heat peaks in August around 80°F, which confines cool-season crops to the shoulders of summer. Fontana beds by a wall stay warmer at night.
Similar climates: Bloomington, CA, Rialto, CA, Rancho Cucamonga, CA, Jurupa Valley, CA, Muscoy, CA.
Frequently asked
- When does it freeze in Fontana?
- Most years Fontana doesn't freeze: the nearest NOAA station reached 32°F in 41% of 1991–2020 years, so Fontana has no reliable frost date.
- What is the rainy season in Fontana?
- Fontana sees its heaviest rain in February (around 3.4 inches), part of roughly 17 inches a year.
- What is the warmest month in Fontana?
- On average August tops the year in Fontana at about 80°F.
- What is the coldest month in Fontana?
- The coldest stretch in Fontana falls in January, around 52°F on average.
- When can I start a vegetable garden in Fontana?
- Any season works in Fontana: without a reliable freeze, Fontana's heat, not frost, decides when greens and tomatoes do best.
- What hardiness zone is Fontana?
- With January around 52°F, Fontana's zone reflects that minimum — the USDA ZIP map confirms Fontana's band.
- What is the 10-day forecast for Fontana?
- Fontana'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 Fontana?
- See this week's day-by-day rain chances for Fontana in the daily forecast above, and the next 24 hours in the hourly chart.
- What is the weather like right now in Fontana?
- Current conditions for Fontana and the next 24 hours — temperature, precipitation chance, and wind by the hour — are in the hourly forecast chart above.
- How often is the Fontana forecast updated?
- The Fontana forecast on this page is built from Open-Meteo weather-model data and refreshes regularly through the day.
- When are sunrise and sunset in Fontana?
- Today's sunrise and sunset times for Fontana 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 Fontana?
- The next few days in Fontana's forecast are the most reliable; accuracy declines beyond about a week as weather-model uncertainty grows.
Fontana sits at 34.1°N; its climate zone is hot-summer Mediterranean (Köppen approximation).
ZIP codes in Fontana
- 92331
- 92334
- 92335
- 92336
- 92337
- 92402