Riverside, CA Weather
Riverside hourly forecast: next 24 hours
Today's high of 83°F (28°C) is about 9°F (5°C) below the typical September high of 92°F (33°C).
Current conditions in detail
Riverside weather tomorrow (Thursday, September 17)
Tomorrow in Riverside looks sunny, with a high of 83° and an overnight low of 65°. Rain is unlikely (1% chance). Winds top out near 12 mph, and the UV index reaches 8 (very high).
Riverside 14-day forecast
About the weather in Riverside
The number that shapes daily life in Riverside is not the seasonal one but the daily one: afternoons run about 14°C warmer than the nights that follow them, every month of the year. August pairs highs of 96°F (35°C) with lows of 67°F (19°C); January pairs 65°F (18°C) with 44°F (7°C).
Riverside weather: quick facts
- Hottest month: August - highs near 96°F (35°C)
- Coldest month: January - highs near 65°F (18°C)
- Decade extremes (2015-2024): 116°F (47°C) high · 28°F (-2°C) low
- Wettest month: January (6 rainy days) · Sunniest: July (13.7 h sun/day)
- Climate type: semi-arid
- Annual swing: 14°C between the average warmest and coolest month · day to night: 14°C
- Months averaging 30°C or hotter: 4
- Average humidity: 56%
Temperatures through the year
Sunshine averages 10.8 hours a day over the year - sunnier than 91% of the 3496 cities in our dataset, peaking in July at 13.7 hours. January bottoms out at 65°F (18°C) in daylight, 44°F (7°C) after dark. At its warmest, in August, Riverside runs to 96°F (35°C) in the afternoon and back to 67°F (19°C) by dawn. The wettest month is January (3.4 inches (87 mm) across 6 days) and the driest June.
Rain, sun and snow
Average highs hold at or above 30°C for 4 months of the year, June through September being the unbroken run. Days and nights are about 14°C apart on average - wider than almost anywhere else we cover. Relative humidity averages 56% across the year, drier than all but 10% of the 3496 cities in our dataset. Across the gridded 2015-2024 daily record, the highest daily maximum for this location was 116°F (47°C) and the lowest daily minimum 28°F (-2°C).
Season by season
Spring (March through May)
Through spring, Riverside is pleasantly warm: 75°F (24°C) by day, 51°F (11°C) after dark, and rain comes on about 14 days over the three months. Daylight is generous - around 11.2 hours of sun a day.
Summer (June through August)
Summer in Riverside runs at full heat, with daytime highs averaging 93°F (34°C) and nights around 64°F (18°C); precipitation is sparse, near 11 mm (0.4 in) for the season. Daylight is generous - around 13.2 hours of sun a day.
Fall (September through November)
Through fall, Riverside brings hot afternoons: 83°F (29°C) by day, 57°F (14°C) after dark, and precipitation is sparse, near 2.0 inches (51 mm) for the season. Daylight is generous - around 10.3 hours of sun a day.
Winter (December through February)
Winter in Riverside stays on the cool side of mild, with daytime highs averaging 66°F (19°C) and nights around 44°F (7°C); rain comes on about 17 days over the three months.
Average temperatures in Riverside by month
| Month | High | Low | Rain days | Precipitation | Sunshine | Humidity |
|---|---|---|---|---|---|---|
| January | 65° | 44° | 6 | 3.4 in | 8.3 h/day | 63% |
| February | 68° | 45° | 6 | 2.6 in | 9.0 h/day | 58% |
| March | 70° | 47° | 8 | 2.7 in | 10.2 h/day | 64% |
| April | 77° | 52° | 3 | 0.8 in | 11.3 h/day | 57% |
| May | 79° | 54° | 3 | 0.5 in | 12.0 h/day | 62% |
| June | 89° | 60° | 0 | 0.0 in | 13.3 h/day | 55% |
| July | 95° | 65° | 0 | 0.2 in | 13.7 h/day | 52% |
| August | 96° | 67° | 1 | 0.2 in | 12.7 h/day | 51% |
| September | 92° | 64° | 2 | 0.4 in | 11.3 h/day | 53% |
| October | 84° | 58° | 2 | 0.6 in | 10.3 h/day | 49% |
| November | 74° | 49° | 3 | 1.0 in | 9.4 h/day | 46% |
| December | 66° | 44° | 5 | 2.4 in | 8.2 h/day | 56% |