Riverside climate
Riverside (California, United States) has a hot semi-arid climate (Köppen BSh). The average temperature over the year is 20 °C68 °F, and about 289 mm11 in of precipitation falls in an average year.
Temperature by month
Precipitation by month
Riverside climate table
| Month | High °C°F | Low °C°F | Mean °C°F | Precip. mmin |
|---|---|---|---|---|
| Jan | 1967 | 744 | 1355 | 582.3 |
| Feb | 2067 | 744 | 1356 | 632.5 |
| Mar | 2373 | 947 | 1660 | 321.3 |
| Apr | 2577 | 1050 | 1763 | 180.7 |
| May | 2883 | 1355 | 2169 | 70.3 |
| Jun | 3391 | 1661 | 2476 | 10.0 |
| Jul | 3697 | 2068 | 2882 | 50.2 |
| Aug | 3697 | 2068 | 2883 | 30.1 |
| Sep | 3494 | 1966 | 2780 | 40.2 |
| Oct | 2984 | 1458 | 2271 | 150.6 |
| Nov | 2374 | 1050 | 1762 | 240.9 |
| Dec | 1965 | 643 | 1254 | 582.3 |
| Year | 3697 | 643 | 2068 | 28911 |
“Year” row: highest monthly high, lowest monthly low, annual mean and annual total.
| Month | Humid. | Cloud | Solar | Daylight |
|---|---|---|---|---|
| Jan | 55% | 41% | 3.2 | 10:07 |
| Feb | 59% | 43% | 4.1 | 10:55 |
| Mar | 59% | 43% | 5.4 | 11:53 |
| Apr | 57% | 40% | 6.5 | 12:59 |
| May | 55% | 43% | 6.9 | 13:55 |
| Jun | 47% | 42% | 7.3 | 14:24 |
| Jul | 41% | 35% | 7.4 | 14:12 |
| Aug | 38% | 29% | 7.1 | 13:24 |
| Sep | 40% | 28% | 6.0 | 12:20 |
| Oct | 45% | 33% | 4.6 | 11:16 |
| Nov | 47% | 36% | 3.6 | 10:21 |
| Dec | 54% | 42% | 2.9 | 9:54 |
Humid. = average relative humidity at 2 m; cloud = average cloud amount; solar = average daily solar energy reaching the ground in kWh/m² (all-sky); daylight in hours:minutes, calculated for the 15th of each month.
What the climate of Riverside is like
The warmest month is August, with an average high of 36 °C97 °F and a low of 20 °C68 °F. The coldest is December, when highs average 19 °C65 °F and lows 6 °C43 °F. There is a clear seasonal cycle, with 15.7 °C28.3 °F between the average temperature of the warmest and the coolest month.
It is dry, with about 289 mm11 in of precipitation per year. The wettest three-month stretch is December–February, which brings 62% of the annual total. Months with less than 20 mm0.8 in on average: April–October. The wettest month is February (63 mm2.5 in), the driest is June (1 mm0.0 in).
Relative humidity ranges from 38% in August to 59% in February. The clearest skies (lowest average cloud amount, 28%) are typical of September. Average wind speed near the ground ranges from 6 km/h (4 mph) in September to 7 km/h (4 mph) in April. Daylight lasts from about 9.9 hours in December to 14.4 hours in June.
Best time to visit Riverside
Based on these averages, the most comfortable months for sightseeing and outdoor activities are October–May: average highs of 19 °C65 °F to 29 °C84 °F with 7 mm0.3 in to 63 mm2.5 in of precipitation per month.
The most challenging month is August, which is hot, with average highs of 36 °C97 °F.
Comfort score: months are ranked by how close they come to an average high of 21–28 °C (70–82 °F), lows above 5 °C (41 °F), little precipitation and moderate humidity. The best-ranked months of each place are recommended, even where none meets all of these. These are general rules of thumb applied to long-term averages.
What to pack for Riverside
- Winter (December–February) — highs 1965 to 20 °C67 °F, lows 643 to 7 °C44 °F, about 60 mm2.3 in of precipitation a month. Pack light layers — T-shirts plus a light sweater or jacket and an extra layer for the cooler mornings and evenings.
- Spring (March–May) — highs 2373 to 28 °C83 °F, lows 947 to 13 °C55 °F, about 19 mm0.8 in of precipitation a month. Pack light summer clothes such as T-shirts, shorts or light dresses and an extra layer for the cooler mornings and evenings.
- Summer (June–August) — highs 3391 to 36 °C97 °F, lows 1661 to 20 °C68 °F, about 3 mm0.1 in of precipitation a month. Pack very light, breathable clothing, a sun hat and plenty of water.
- Autumn (September–November) — highs 2374 to 34 °C94 °F, lows 1050 to 19 °C66 °F, about 15 mm0.6 in of precipitation a month. Pack light summer clothes such as T-shirts, shorts or light dresses and an extra layer for the cooler mornings and evenings.
How Riverside compares
Compared with Anaheim, about 50 km to the west, Riverside has practically the same average temperature and receives 13% less precipitation (289 mm11 in vs 331 mm13 in). The difference is largest in July (2.2 °C4 °F warmer).
Of the 222 places in the United States covered by World Climates, Riverside is the 37th warmest by annual mean temperature and the 207th wettest by annual precipitation. See all of them on the United States climate page.
Places in other countries with the most similar temperature and rainfall pattern: Beersheba (Israel, BSh), Rishon LeTsiyyon (Israel, BSh) and Netanya (Israel, Csa).
The same NASA POWER grid cell also contains Moreno Valley (pop. 204,198) and Corona (pop. 164,226). Their long-term averages in this dataset are essentially the same as for Riverside, so they do not have separate pages.
Nearby places
- San Bernardino 20 km · 19 °C67 °F · 289 mm11 in
- Murrieta 48 km · 17 °C63 °F · 298 mm12 in
- Santa Ana 49 km · 17 °C63 °F · 311 mm12 in
- Anaheim 50 km · 20 °C67 °F · 331 mm13 in
- West Covina 52 km · 19 °C67 °F · 331 mm13 in
- Temecula 56 km · 20 °C68 °F · 299 mm12 in
- Victorville 66 km · 17 °C63 °F · 235 mm9.3 in
- Long Beach 76 km · 20 °C68 °F · 331 mm13 in
Frequently asked questions
What is the warmest month in Riverside?
August is the warmest month in Riverside, with an average high of 36 °C (97 °F) and an average low of 20 °C (68 °F).
What is the coldest month in Riverside?
December is the coldest month, with an average high of 19 °C (65 °F) and an average low of 6 °C (43 °F).
When does it rain the most in Riverside?
February is the wettest month with about 63 mm (2.5 in) of precipitation; June is the driest with about 1 mm (0.0 in).
What is the best time to visit Riverside?
Judging by long-term averages, the most comfortable months are October–May.
About this data
All figures are 25-year averages (January 2001 – December 2025) from the NASA POWER project. Temperature, humidity, wind and precipitation come from the MERRA-2 reanalysis (precipitation is the bias-corrected MERRA-2 product), cloud and solar values from CERES satellite data. They describe a grid cell of roughly 50–70 km, not a single weather station, so they can differ from airport records — most of all on coasts, in mountains and for rainfall. Average highs and lows are the monthly mean temperature plus/minus half of the average daily temperature range. Counts of rainy days are not part of this dataset.
The grid cell’s average elevation is 628 m, while Riverside lies at about 252 m. Temperatures on this page were therefore adjusted by +2.4 °C4.4 °F using the standard lapse rate of 6.5 °C per 1,000 m.