Fontana, California Weather
Coastal fog thickens at dawn. Day 78 of spring. Read this microseason across nine climate regions →
Fontana weather forecast — hour by hour, 7-day outlook, NOAA radar
- TodayJun 4Mostly Clear——92°58°—
- FridayJun 5Foggy——90°58°-2°
- SaturdayJun 6Foggy——85°57°-5°
- SundayJun 7Mostly Clear——82°64°-3°
- MondayJun 8Overcast——81°63°-1°
- TuesdayJun 9Partly Cloudy——78°63°-3°
- WednesdayJun 10Partly Cloudy——85°63°+7°
Ozone at AQI 500 — peak already passed at 1 PM under clear skies. AQI up 34 in the last 6 hours — air quality is degrading. Levels should ease through evening.
AVOID OUTDOORS Avoid outdoor exertion. Keep windows closed; use HEPA filtration indoors if available.
What's driving it
Ozone × UV × Sky
Ozone at AQI 500 — peak already passed at 1 PM under clear skies. Levels should ease through evening.
- Present
- AQI 500
- UV peak
- 2.0 at earlier today
- Sky at peak
- clear
- Projected peak
- AQI 500
PM × Wind × Precip
PM2.5/PM10 ratio 0.70 with 12 mph wind — characteristic of long-range haze transport rather than a local source.
- PM2.5/PM10
- 0.70
- Wind
- breezy
- Recent rain
- 0h in last 6h
- Pattern
- transport
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
- 6:39 AM
- Moonset
- 5:14 PM
- In sign
- ♒︎ Aquarius
Coastal fog thickens at dawn
Fontana at a glance
- Today vs. normal: 7°F above the seasonal normal for this latitude
- Last frost: March 12 (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
August brings Fontana's peak heat with temperatures averaging around 81°F, while December delivers the year's coldest weather at roughly 56°F. February sees the heaviest rainfall at 2.5 inches, contrasting sharply with June's minimal 0.1 inches.
| Month | Mean temp | Precip | Rainy days |
|---|---|---|---|
| January | 56° | 2.2″ | 4 |
| February | 57° | 2.5″ | 5 |
| March | 60° | 1.6″ | 3 |
| April | 64° | 0.6″ | 1 |
| May | 68° | 0.2″ | 1 |
| June | 74° | 0.1″ | 0 |
| July | 80° | 0.1″ | 0 |
| August | 81° | 0.1″ | 0 |
| September | 77° | 0.1″ | 0 |
| October | 69° | 0.4″ | 1 |
| November | 61° | 0.7″ | 2 |
| December | 56° | 1.4″ | 3 |
Regional context
Located within a hot-summer Mediterranean climate region, Fontana shares temperature ranges, seasonal patterns, and growing conditions with surrounding cities in this climate zone.
Similar climates: Los Angeles, CA, San Francisco, CA, San Diego, CA, Riverside, CA, Sacramento, 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?
- Spring's final frost usually occurs around mid-March in Fontana, while the first fall frost typically arrives around mid-December.
- What is the rainy season in Fontana?
- February stands as the wettest month, delivering about 2.5 inches of rain on average, while the city's total annual rainfall reaches roughly 10 inches.
- What is the warmest month in Fontana?
- August typically records the year's highest temperatures, averaging about 81°F.
- What is the coldest month in Fontana?
- December usually brings the coldest weather, with temperatures averaging about 56°F.
- When can I start a vegetable garden in Fontana?
- Cool-season crops like peas and lettuce can be planted around the last spring frost in mid-March, while warm-season varieties such as tomatoes and peppers should wait 1–2 weeks after that date.
- How many rainy days does Fontana get?
- Fontana experiences about 19 rainy days per year on average.
- What hardiness zone is Fontana?
- Fontana's USDA hardiness zone depends on its lowest average winter temperature; the USDA's online lookup tool using the city ZIP code provides the current zone designation.
Climate
Fontana, California experiences a hot-summer Mediterranean climate. January temperatures hover near 56°F, while July averages 80°F, creating a 23°F seasonal swing.
Annual precipitation totals about 10 inches, distributed across roughly 19 rainy days throughout the year.
Weather patterns depend on the city's latitude at 34.1°N, its proximity to large water bodies, and local elevation. These factors determine growing conditions, frost timing, and daily weather variations.