Riverside climate
Riverside is warmest in August, with average highs of 34 °C, and coldest in December, when nights average 5.0 °C. February is the wettest month (108 mm) and August the driest (1.0 mm). Figures are 1991–2020 climate normals.
Across a full year Riverside averages 439 mm of rain, 189 days above 25 °C and 6 days below freezing.
United States · 252 m elevation · population 317,261 · 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 5.0 °C
- Driest month August 1 mm
- Wettest month February 108 mm
- Least cloud August 13 % cloud
- Hottest on record September 47 °C
- Coldest on record January -3.9 °C
What to expectRiverside through the year
Riverside has a clear annual cycle: average daily highs run from 18 °C in December to 34 °C in August, a swing of 16 °C in mean temperature across the year.
Counted across a normal year, 189 days a year reach 25 °C, 113 of them reach 30 °C, 6 nights drop below freezing. The warmest reading in the 1991–2020 record is 47 °C, in September.
Rain is strongly seasonal. February averages 108 mm against 1 mm in August — 110 times as much. Planning around the dry months matters more here than planning around temperature.
Month by month
| Month | Avg high | Rainfall | Cloud |
|---|---|---|---|
| January | 18.1 °C | 92 mm | 49 % |
| February | 18.7 °C | 108 mm | 51 % |
| March | 20.7 °C | 64 mm | 50 % |
| April | 23.4 °C | 31 mm | 42 % |
| May | 26.0 °C | 14 mm | 37 % |
| June | 29.9 °C | 3 mm | 21 % |
| July | 33.0 °C | 2 mm | 18 % |
| August | 34.1 °C | 1 mm | 13 % |
| September | 32.5 °C | 5 mm | 17 % |
| October | 27.6 °C | 22 mm | 27 % |
| November | 22.3 °C | 29 mm | 36 % |
| December | 17.7 °C | 67 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 | 18.1 °C | 5.1 °C | 10.7 °C | 30.3 °C | -3.9 °C | 1 | 0 | 2 |
| February | 18.7 °C | 6.0 °C | 11.6 °C | 30.1 °C | -2.5 °C | 4 | 0 | 1 |
| March | 20.7 °C | 7.8 °C | 13.6 °C | 33.3 °C | -0.3 °C | 6 | 1 | 0 |
| April | 23.4 °C | 9.7 °C | 15.8 °C | 36.1 °C | 0.5 °C | 12 | 3 | 0 |
| May | 26.0 °C | 12.5 °C | 18.5 °C | 38.6 °C | 5.2 °C | 18 | 7 | 0 |
| June | 29.9 °C | 15.4 °C | 21.9 °C | 43.6 °C | 7.4 °C | 26 | 14 | 0 |
| July | 33.0 °C | 18.7 °C | 25.2 °C | 46.0 °C | 12.3 °C | 31 | 25 | 0 |
| August | 34.1 °C | 19.5 °C | 26.1 °C | 43.5 °C | 12.7 °C | 31 | 28 | 0 |
| September | 32.5 °C | 17.5 °C | 24.3 °C | 46.6 °C | 9.0 °C | 28 | 22 | 0 |
| October | 27.6 °C | 13.1 °C | 19.7 °C | 41.3 °C | 2.5 °C | 21 | 10 | 0 |
| November | 22.3 °C | 8.4 °C | 14.5 °C | 34.6 °C | -1.8 °C | 9 | 2 | 0 |
| December | 17.7 °C | 5.0 °C | 10.5 °C | 28.9 °C | -3.4 °C | 1 | 0 | 3 |
Rain, sun and wind month by month
| Month | Rainfall | Wet days | Daylight | Cloud cover | Humidity | Wind |
|---|---|---|---|---|---|---|
| January | 92 mm | 7 | 10 h/day | 49 % | 65 % | 9.6 km/h |
| February | 108 mm | 8 | 11 h/day | 51 % | 67 % | 10 km/h |
| March | 64 mm | 7 | 12 h/day | 50 % | 68 % | 11 km/h |
| April | 31 mm | 5 | 13 h/day | 42 % | 63 % | 13 km/h |
| May | 14 mm | 3 | 14 h/day | 37 % | 62 % | 13 km/h |
| June | 3 mm | 1 | 14 h/day | 21 % | 57 % | 12 km/h |
| July | 2 mm | 1 | 14 h/day | 18 % | 54 % | 12 km/h |
| August | 1 mm | 0 | 13 h/day | 13 % | 52 % | 12 km/h |
| September | 5 mm | 1 | 12 h/day | 17 % | 53 % | 12 km/h |
| October | 22 mm | 3 | 11 h/day | 27 % | 54 % | 11 km/h |
| November | 29 mm | 4 | 10 h/day | 36 % | 56 % | 9.9 km/h |
| December | 67 mm | 6 | 9.9 h/day | 44 % | 62 % | 9.8 km/h |
How Riverside 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 |
|---|---|---|---|---|
| Riverside | 34 °C | 5.0 °C | 439 mm | 189 |
| Moreno Valley · United States | 33 °C | 4.6 °C | 391 mm | 174 |
| Fontana · United States | 34 °C | 4.8 °C | 464 mm | 180 |
| Corona · United States | 33 °C | 6.1 °C | 438 mm | 189 |
| San Bernardino · United States | 34 °C | 5.0 °C | 392 mm | 186 |
| Ontario · United States | 33 °C | 6.4 °C | 418 mm | 181 |
| Pomona · United States | 32 °C | 6.4 °C | 411 mm | 176 |
Where Riverside ranks
| Ranking | Position | Value |
|---|---|---|
| Places with the best weather in North America in April | 10thof 50 | 95/100 |
| The driest places in North America in August | 15thof 50 | 1.0 mm |
| The warmest places in North America in September | 22ndof 50 | 32 °C |
| Places with the best weather in North America in May | 23rdof 50 | 92/100 |
| The driest places in North America in July | 24thof 50 | 2.1 mm |
| The driest places in North America in June | 28thof 50 | 3.4 mm |
Planning a trip? See the best time to visit Riverside.
QuestionsCommon questions about Riverside’s climate
When is the best time to visit Riverside?
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 Riverside get?
In August, the warmest month, daily highs average 34 °C. About 113 days a year pass 30 °C. The highest value in the 1991–2020 record is 47 °C.
How cold does it get in winter?
Nights average 5.0 °C in December, the coldest month. A normal year has 6 nights below freezing.
Which month is wettest in Riverside?
February, averaging 108 mm over 8 days with rain. The driest month is August with 1 mm. The year as a whole averages 439 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 Riverside 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
- 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.