Fontana, California Weather
August begins in scorching stillness. Day 43 of summer. Read this microseason across nine climate regions →
Fontana weather forecast — hour by hour, 7-day outlook, NOAA radar
- TodayAug 2Clear——102°68°—
- MondayAug 3Clear——99°66°-3°
- TuesdayAug 4Clear——101°67°+2°
- WednesdayAug 5Clear——100°82°-1°
- ThursdayAug 6Clear——100°81°0°
- FridayAug 7Clear——100°81°0°
- SaturdayAug 8Clear——100°81°0°
AQI 65 (Moderate), driven by PM2.5. AQI flat over the last 6 hours (within ±3 points). PM2.5 at 21.2 µg/m³ (AQI 74) with a 0.85 fine-to-coarse ratio and 0 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 21.2 µg/m³ (AQI 74) with a 0.85 fine-to-coarse ratio and 0 mph wind — combustion smoke trapped in stagnant air, not road dust.
- PM2.5/PM10
- 0.85
- 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).
Red sky at night, sailor's delight.
- Moonrise
- 9:34 PM
- Moonset
- 9:59 AM
- In sign
- ♓︎ Pisces
August begins in scorching stillness
Fontana at a glance
- Today vs. normal: 5°F above the seasonal normal for this latitude
- Last frost: March 12 (climatological average for this latitude)
- Microseason: Aug 1–5
- Planting window: Sow fall peas. Start kale and collard seedlings for fall.
ZIP codes: 92335, 92336, 92337
16-Day Forecast — Fontana
- Sun102°68°0%
- Mon99°66°0%
- Tue101°67°0%
- Wed100°82°0%
- Thu100°81°1%
- Fri100°81°1%
- Sat100°81°2%
- Sun98°79°2%
- Mon94°77°1%
- Tue94°76°0%
- Wed94°77°1%
- Thu95°76°3%
- Fri97°78°17%
- Sat94°80°12%
- Sun99°79°3%
- Mon99°80°10%
Forecast data from Open-Meteo (CC BY 4.0).
Live wind & temperature near Fontana
Right now in the garden
Peak growing season
As of August 2, 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.
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’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.
Microseason · August 1–5
August begins in scorching stillness
Calm days dominate early August; temperatures peak; the entire ecosystem is in survival mode.
Day 214 of 365 · Wedge 43 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
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 | Rainy days |
|---|---|---|---|
| January | 52° | 3.3″ | 11 |
| February | 54° | 3.4″ | 10 |
| March | 57° | 3.0″ | 13 |
| April | 62° | 1.5″ | 10 |
| May | 67° | 0.5″ | 7 |
| June | 73° | 0.1″ | 3 |
| July | 79° | 0.1″ | 1 |
| August | 80° | 0.0″ | 1 |
| September | 76° | 0.1″ | 2 |
| October | 69° | 0.5″ | 5 |
| November | 59° | 1.6″ | 8 |
| December | 53° | 2.6″ | 10 |
Regional context
Fontana's climate, from NOAA NCEI 1991-2020 station normals, pairs 52°F Januarys with 79°F Julys — a 27°F swing. About 16.7 inches of precipitation falls over roughly 82 days a year.
Fontana's moisture rides winter storm tracks: February brings 3.4 inches over 9.9 wet days, while August sees only 0.0 inches across 0.9 days 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. Across Fontana, elevation and tree cover drive a 4-7°F spread in Fontana's overnight lows.
Similar climates: Bloomington, CA, Rialto, CA, Rancho Cucamonga, CA, Jurupa Valley, CA, Muscoy, CA.
Naturalist notes
Late May brings the peak blooming period for California poppies across the region's hillsides and open spaces.
Western bluebirds typically begin their second nesting cycle during June in suitable oak woodland habitats.
Frequently asked
- When does it freeze in Fontana?
- Frost typically leaves Fontana by mid-March and returns to Fontana near mid-December.
- 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?
- Hardy spring crops go in near mid-March in Fontana; tender peppers and squash wait 10–14 days.
- How many rainy days does Fontana get?
- Fontana averages about 82 days with measurable rain or snow each year.
- 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.
Climate
In Fontana, California, the hot-summer Mediterranean climate runs from about 52°F in January to 79°F in July, a 27°F seasonal range.
Across the year, Fontana collects about 17 inches of precipitation over roughly 82 days with measurable rain or snow.
Fontana's 27°F range, set by its 34.1°N position, drives frost timing and what thrives in Fontana.
ZIP codes in Fontana
- 92335
- 92336
- 92337
- 92331
- 92334
- 92402