Climate averages 1991–2020
Riverside weather
in January.
A mild, wet month: the 11th warmest and the 11th driest of the year.
Long-term climate patterns, not a forecast for a particular trip.
January is a mild month in Riverside: daytime highs average 17.4°C and nights cool to about 4.7°C. By daytime temperature it is the 11th warmest of the 12 months.
Expect about 96 mm of rain on roughly 7 days, which makes January a wet month (the 11th driest of the 12 months). Daylight, from sunrise to sunset, lasts about 10 h 10 min on an average January day.
The nearest other city in this atlas is Moreno Valley (15 km away). In January its highs average 16.6°C, 0.8°C cooler than Riverside, with 74 mm of rain.
Among the 498 cities listed in the United States, Riverside ranks joint 87th of 498 for the warmest January highs and joint 409th of 498 for the driest January (rainfall, lowest first). The mean January high of those 498 cities is 9.5°C; Riverside is 7.9°C warmer than that mean.
From January to February, average highs rise by 0.4°C to 17.8°C, and monthly rainfall rises from 96 mm to 111 mm.
The annual picture
January in context
Monthly rainfall
Average total · mmAverages from hourly ERA5 reanalysis data. Actual weather varies from year to year. How these numbers are calculated
Every month, side by side
Riverside climate table
| Month | Average highHigh / low | Average low | Rainfall mm/month | Rain days ≥1 mm/day | Daylight hours/dayDaylight h/day |
|---|---|---|---|---|---|
| January, selected | 17.4°C4.7°C | 4.7°C | 96 | 6.6 | 10.210 h |
| February | 17.8°C5.7°C | 5.7°C | 111 | 7.4 | 10.911 h |
| March | 19.8°C7.5°C | 7.5°C | 68 | 6.8 | 12.012 h |
| April | 22.4°C9.5°C | 9.5°C | 32 | 4.6 | 13.013 h |
| May | 25.2°C12.3°C | 12.3°C | 15 | 2.6 | 13.914 h |
| June | 29.3°C15.4°C | 15.4°C | 3.4 | 0.5 | 14.414 h |
| July | 32.7°C18.9°C | 18.9°C | 2.2 | 0.5 | 14.214 h |
| August | 33.8°C19.7°C | 19.7°C | 1.1 | 0.3 | 13.413 h |
| September | 32.0°C17.5°C | 17.5°C | 5.5 | 1.2 | 12.412 h |
| October | 26.9°C12.7°C | 12.7°C | 22 | 3.1 | 11.411 h |
| November | 21.6°C8.0°C | 8.0°C | 30 | 3.5 | 10.410 h |
| December | 17.1°C4.5°C | 4.5°C | 67 | 5.8 | 9.910 h |
Rainfall is the average of the 30 separate monthly totals. A rain day is a local calendar day with at least 1 mm of precipitation. Daylight is the calculated sunrise-to-sunset length, not measured sunshine.
Compare places
January in nearby cities
- Moreno Valley in JanuaryUnited States · 15 kmHigh 16.6°C · Low 4.4°C · 74 mm rain
- Fontana in JanuaryUnited States · 16 kmHigh 16.7°C · Low 4.3°C · 96 mm rain
- Corona in JanuaryUnited States · 18 kmHigh 18.3°C · Low 5.8°C · 96 mm rain
- San Bernardino in JanuaryUnited States · 20 kmHigh 16.9°C · Low 4.7°C · 74 mm rain
- Redlands in JanuaryUnited States · 23 kmHigh 16.8°C · Low 5.2°C · 74 mm rain
- Perris in JanuaryUnited States · 24 kmHigh 16.8°C · Low 4.2°C · 83 mm rain
- Rancho Cucamonga in JanuaryUnited States · 25 kmHigh 17.2°C · Low 5.6°C · 96 mm rain
- Ontario in JanuaryUnited States · 26 kmHigh 17.5°C · Low 6.4°C · 93 mm rain
Read the numbers correctly
Climate, not a promise.
These patterns help compare months. They cannot tell you the weather on a specific day of your trip.
Sources, method and limitsHow these numbers are made (what the highs, lows and rain days mean, the sources and the model cell used for Riverside) is explained once on the Riverside year overview and on the Sources, method and limits page.
Fontana, Rancho Cucamonga and Corona lie in the same rainfall cell, so their rainfall figures are identical to these; temperatures differ because they come from smaller 0.1° cells.