Fontana climate
Fontana is warmest in August, with average highs of 34 °C, and coldest in December, when nights average 4.8 °C. February is the wettest month (112 mm) and August the driest (1.1 mm). Figures are 1991–2020 climate normals.
Across a full year Fontana averages 464 mm of rain, 180 days above 25 °C and 7 days below freezing.
United States · 377 m elevation · population 212,704 · 1991–2020 normals
Temperature below 0 °C to above 30 °C Rain band height is that month’s share of the wettest month
- Warmest month August 34 °C
- Coldest month December 4.8 °C
- Driest month August 1 mm
- Wettest month February 112 mm
- Least cloud August 13 % cloud
- Hottest on record September 46 °C
- Coldest on record January -4.2 °C
What to expectFontana through the year
Fontana has a clear annual cycle: average daily highs run from 17 °C in December to 34 °C in August, a swing of 16 °C in mean temperature across the year.
Counted across a normal year, 180 days a year reach 25 °C, 109 of them reach 30 °C, 7 nights drop below freezing. The warmest reading in the 1991–2020 record is 46 °C, in September.
Rain is strongly seasonal. February averages 112 mm against 1 mm in August — 103 times as much. Planning around the dry months matters more here than planning around temperature.
Month by month
| Month | Avg high | Rainfall | Cloud |
|---|---|---|---|
| January | 17.3 °C | 99 mm | 49 % |
| February | 17.9 °C | 112 mm | 51 % |
| March | 20.0 °C | 70 mm | 50 % |
| April | 22.8 °C | 32 mm | 42 % |
| May | 25.6 °C | 15 mm | 37 % |
| June | 29.6 °C | 4 mm | 20 % |
| July | 32.8 °C | 2 mm | 17 % |
| August | 33.8 °C | 1 mm | 13 % |
| September | 32.1 °C | 5 mm | 17 % |
| October | 27.0 °C | 22 mm | 27 % |
| November | 21.5 °C | 32 mm | 36 % |
| December | 16.9 °C | 68 mm | 44 % |
Temperature month by month
| Month | Avg high | Avg low | Mean | Record high | Record low | Days above 25 °C | Days above 30 °C | Days below 0 °C |
|---|---|---|---|---|---|---|---|---|
| January | 17.3 °C | 4.8 °C | 10.1 °C | 29.9 °C | -4.2 °C | 1 | 0 | 3 |
| February | 17.9 °C | 5.6 °C | 11.0 °C | 29.1 °C | -2.7 °C | 3 | 0 | 1 |
| March | 20.0 °C | 7.2 °C | 13.0 °C | 32.5 °C | -0.4 °C | 5 | 1 | 0 |
| April | 22.8 °C | 9.1 °C | 15.3 °C | 35.6 °C | 0.1 °C | 11 | 3 | 0 |
| May | 25.6 °C | 11.9 °C | 18.1 °C | 38.2 °C | 4.5 °C | 17 | 7 | 0 |
| June | 29.6 °C | 15.1 °C | 21.8 °C | 43.3 °C | 6.5 °C | 25 | 14 | 0 |
| July | 32.8 °C | 18.8 °C | 25.3 °C | 45.6 °C | 11.3 °C | 31 | 25 | 0 |
| August | 33.8 °C | 19.4 °C | 26.1 °C | 43.3 °C | 12.3 °C | 31 | 27 | 0 |
| September | 32.1 °C | 17.2 °C | 24.2 °C | 46.2 °C | 8.7 °C | 28 | 22 | 0 |
| October | 27.0 °C | 12.7 °C | 19.3 °C | 40.4 °C | 2.3 °C | 20 | 9 | 0 |
| November | 21.5 °C | 8.1 °C | 14.0 °C | 33.6 °C | -3.1 °C | 8 | 1 | 0 |
| December | 16.9 °C | 4.8 °C | 9.9 °C | 27.7 °C | -3.7 °C | 1 | 0 | 3 |
Rain, sun and wind month by month
| Month | Rainfall | Wet days | Daylight | Cloud cover | Humidity | Wind |
|---|---|---|---|---|---|---|
| January | 99 mm | 7 | 10 h/day | 49 % | 64 % | 9.9 km/h |
| February | 112 mm | 8 | 11 h/day | 51 % | 65 % | 10 km/h |
| March | 70 mm | 7 | 12 h/day | 50 % | 67 % | 11 km/h |
| April | 32 mm | 5 | 13 h/day | 42 % | 61 % | 13 km/h |
| May | 15 mm | 3 | 14 h/day | 37 % | 61 % | 12 km/h |
| June | 4 mm | 1 | 14 h/day | 20 % | 55 % | 12 km/h |
| July | 2 mm | 1 | 14 h/day | 17 % | 51 % | 11 km/h |
| August | 1 mm | 0 | 13 h/day | 13 % | 48 % | 11 km/h |
| September | 5 mm | 1 | 12 h/day | 17 % | 49 % | 11 km/h |
| October | 22 mm | 3 | 11 h/day | 27 % | 50 % | 11 km/h |
| November | 32 mm | 4 | 10 h/day | 36 % | 53 % | 9.9 km/h |
| December | 68 mm | 6 | 9.9 h/day | 44 % | 60 % | 10 km/h |
How Fontana compares
The same four figures for nearby destinations, so the numbers above have something to be read against. Summer high is the warmest month's average high; winter low is the coldest month's average low.
| Destination | Summer high | Winter low | Rain per year | Days above 25 °C |
|---|---|---|---|---|
| Fontana | 34 °C | 4.8 °C | 464 mm | 180 |
| San Bernardino · United States | 34 °C | 5.0 °C | 392 mm | 186 |
| Riverside · United States | 34 °C | 5.0 °C | 439 mm | 189 |
| Ontario · United States | 33 °C | 6.4 °C | 418 mm | 181 |
| Moreno Valley · United States | 33 °C | 4.6 °C | 391 mm | 174 |
| Corona · United States | 33 °C | 6.1 °C | 438 mm | 189 |
| Pomona · United States | 32 °C | 6.4 °C | 411 mm | 176 |
Where Fontana ranks
| Ranking | Position | Value |
|---|---|---|
| Places with the best weather in North America in April | 11th of 50 | 95/100 |
| Places with the best weather in North America in May | 18th of 50 | 93/100 |
| The driest places in North America in August | 22nd of 50 | 1.1 mm |
| The driest places in North America in July | 25th of 50 | 2.1 mm |
| The warmest places in North America in September | 28th of 50 | 32 °C |
| The driest places in North America in September | 31st of 50 | 5.5 mm |
Planning a trip? See the best time to visit Fontana.
QuestionsCommon questions about Fontana’s climate
When is the best time to visit Fontana?
That depends on what you want, so the honest answer is a comparison rather than a single month. May, June, October sit closest to 20 °C on average, August is the warmest month and August the driest. The month-by-month table above has the full picture.
How hot does Fontana get?
In August, the warmest month, daily highs average 34 °C. About 109 days a year pass 30 °C. The highest value in the 1991–2020 record is 46 °C.
How cold does it get in winter?
Nights average 4.8 °C in December, the coldest month. A normal year has 7 nights below freezing.
Which month is wettest in Fontana?
February, averaging 112 mm over 8 days with rain. The driest month is August with 1 mm. The year as a whole averages 464 mm.
Are these figures a forecast?
No. They are 1991–2020 climate normals: the average of thirty years, which describes what a month is usually like in Fontana rather than what any particular week will bring. Individual years can differ substantially from the normal.
Data sources and method
- ERA5 / ERA5-Land reanalysis — Copernicus Climate Change Service (C3S), ECMWF. Copernicus Licence
- Open-Meteo — Open-Meteo.com. CC BY 4.0
- NOAA OISST v2.1 — NOAA Physical Sciences Laboratory. Public domain
- GeoNames — GeoNames.org. CC BY 4.0
- Normal period
- 1991–2020
- Data point
- 34.092°, -117.435° , 377 m above sea level (the coordinates the reanalysis values are taken for)
- Dataset version
- era5-1991-2020-scores1.1
- Last processed
Measured values come from ERA5 reanalysis and are reproduced unchanged. Calculated by us: monthly rankings, daylight hours, beach and comfort scores. Full formulas are on the methodology page.
Contains modified Copernicus Climate Change Service information 2026. Neither the European Commission nor ECMWF is responsible for any use that may be made of the Copernicus information or data it contains.