January is one of the cooler months of the year in Riverside, with average highs near 17.5°C and lows around 5°C (mean 11.3°C). It is a relatively wet time of year, averaging 67 mm of rainfall and 57% relative humidity across the period.
January is one of the cooler months of the year in Riverside. Across 45 years of records, the warmest January in Riverside was 2003 — when the month averaged 15.5°C — while the coldest was 1982 at 8.6°C. Typical January days reach 17.5°C with nights near 5°C. The long-term trend is warming, about 0.4°C per decade.
January is a relatively wet time of year in Riverside, averaging 67 mm of rainfall. The wettest January on record was 1993 with 348 mm, while the driest were 2003 and 2014 at 2 mm.
Relative humidity in Riverside during January averages 57%. The most humid January was 1995 at 81%, and the least humid was 2014 at 36%.
January receives about 3.2 kWh/m²/day of solar energy in Riverside. The sunniest January was 2006 at 3.6 kWh/m²/day, and the cloudiest were 1993 and 1995 at 2.6.
Average wind speed in Riverside during January is 2 m/s. The windiest January was 1984 at 2.6 m/s, while the calmest were 1998 and 2015 at 1.4 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 10.4°C | 10.9°C | 11.3°C | 12.1°C | 11.5°C | +1.1°C |
| Avg High | 16.9°C | 16.8°C | 17.5°C | 18.4°C | 17.6°C | +0.7°C |
| Avg Low | 4.0°C | 4.9°C | 5.1°C | 5.8°C | 5.3°C | +1.3°C |
| Avg Rain | 51 mm | 109 mm | 53 mm | 64 mm | 46 mm | -5 mm |
January temperatures in Riverside have risen by about 0.9°C between 1981–1985 and 2021–2025.
January has ranged from a record low of -4.3°C (2007) to a record high of 30°C (2003).
Rainfall in January is a relatively wet time of year, averaging 67 mm, with a wettest year of 348 mm.
A quieter season to visit Riverside
If your dates are flexible, the more temperate months of June and October tend to be the most comfortable for visiting Riverside. That said, January — with days averaging 17.5°C and nights around 5°C (mean 11.3°C) and moderate rainfall (67 mm) — can still be rewarding for travellers who don't mind the cooler conditions, and often means fewer crowds.
| Year | Avg High | Avg Temp | Avg Low | Hottest Day | Coldest Day | Rainfall | Humidity | Wind | Solar |
|---|---|---|---|---|---|---|---|---|---|
| 2025 | 18.3°C | 11.6°C | 4.9°C | 26.5°C | 1.0°C | 15 mm | 44% | 2.1 m/s | 3.5 |
| 2024 | 17.6°C | 11.7°C | 5.8°C | 24.8°C | -0.8°C | 46 mm | 64% | 1.6 m/s | 3.2 |
| 2023 | 13.9°C | 9.1°C | 4.2°C | 19.4°C | -0.9°C | 160 mm | 73% | 2.2 m/s | 2.9 |
| 2022 | 18.8°C | 12.3°C | 5.8°C | 23.0°C | -0.5°C | 3 mm | 54% | 1.8 m/s | 3.3 |
| 2021 | 18.4°C | 11.9°C | 5.4°C | 28.1°C | -1.1°C | 46 mm | 51% | 2.1 m/s | 3.4 |
| 2020 | 18.8°C | 12.2°C | 5.6°C | 24.0°C | 1.3°C | 5 mm | 62% | 1.6 m/s | 3.4 |
| 2019 | 17.1°C | 11.6°C | 6.0°C | 23.9°C | -0.6°C | 108 mm | 65% | 1.8 m/s | 3.1 |
| 2018 | 21.5°C | 14.8°C | 8.2°C | 26.9°C | 0.2°C | 53 mm | 46% | 1.6 m/s | 3.3 |
| 2017 | 14.2°C | 9.5°C | 4.7°C | 22.3°C | -0.9°C | 168 mm | 75% | 2.1 m/s | 2.9 |
| 2016 | 16.7°C | 10.9°C | 5.0°C | 22.9°C | 0.6°C | 84 mm | 65% | 1.6 m/s | 2.9 |
| 2015 | 20.0°C | 13.6°C | 7.1°C | 26.3°C | -2.2°C | 23 mm | 51% | 1.4 m/s | 3.2 |
| 2014 | 22.6°C | 15.4°C | 8.2°C | 26.1°C | 3.5°C | 2 mm | 36% | 1.6 m/s | 3.4 |
| 2013 | 16.7°C | 9.8°C | 2.9°C | 24.5°C | -3.2°C | 26 mm | 48% | 1.9 m/s | 3.4 |
| 2012 | 20.6°C | 13.3°C | 6.1°C | 28.0°C | 0.1°C | 16 mm | 41% | 1.8 m/s | 3.4 |
| 2011 | 17.5°C | 10.9°C | 4.4°C | 26.6°C | -2.1°C | 16 mm | 61% | 1.8 m/s | 3.4 |
| 2010 | 17.3°C | 11.3°C | 5.3°C | 23.9°C | 0.4°C | 148 mm | 61% | 1.9 m/s | 3 |
| 2009 | 19.8°C | 12.9°C | 6.0°C | 25.2°C | -1.8°C | 6 mm | 47% | 2.2 m/s | 3.4 |
| 2008 | 14.5°C | 9.2°C | 3.9°C | 21.6°C | -1.1°C | 166 mm | 66% | 2.5 m/s | 3 |
| 2007 | 15.8°C | 9.4°C | 2.9°C | 25.3°C | -4.3°C | 10 mm | 46% | 2.3 m/s | 3.4 |
| 2006 | 18.2°C | 11.5°C | 4.9°C | 26.7°C | 0.1°C | 31 mm | 52% | 2.1 m/s | 3.6 |
| 2005 | 15.7°C | 10.8°C | 5.8°C | 24.3°C | 0.6°C | 200 mm | 76% | 2 m/s | 2.9 |
| 2004 | 17.8°C | 11.4°C | 5.1°C | 24.6°C | -0.8°C | 9 mm | 52% | 1.6 m/s | 3.4 |
| 2003 🔥 | 22.5°C | 15.5°C | 8.4°C | 30.0°C | 2.1°C | 2 mm | 47% | 1.8 m/s | 3.4 |
| 2002 | 17.2°C | 10.5°C | 3.8°C | 26.3°C | -3.0°C | 13 mm | 49% | 1.8 m/s | 3.3 |
| 2001 | 15.3°C | 9.5°C | 3.7°C | 25.3°C | -1.3°C | 71 mm | 58% | 1.7 m/s | 3.1 |
| 2000 | 18.4°C | 12.3°C | 6.2°C | 24.9°C | 0.9°C | 26 mm | 60% | 1.6 m/s | 3.1 |
| 1999 | 18.7°C | 12.2°C | 5.7°C | 23.8°C | 0.2°C | 31 mm | 53% | 1.8 m/s | 3.2 |
| 1998 | 16.8°C | 11.1°C | 5.4°C | 23.4°C | -1.1°C | 72 mm | 70% | 1.4 m/s | 3 |
| 1997 | 15.5°C | 10.5°C | 5.5°C | 21.4°C | -0.3°C | 118 mm | 73% | 2.3 m/s | 2.8 |
| 1996 | 18.5°C | 12.0°C | 5.5°C | 24.8°C | -1.2°C | 63 mm | 56% | 1.9 m/s | 3.1 |
| 1995 | 13.8°C | 9.3°C | 4.9°C | 23.3°C | -0.4°C | 274 mm | 81% | 2 m/s | 2.6 |
| 1994 | 19.2°C | 12.4°C | 5.5°C | 25.9°C | 0.0°C | 17 mm | 42% | 1.9 m/s | 3.5 |
| 1993 🌧️ | 13.7°C | 9.1°C | 4.5°C | 19.7°C | -2.6°C | 348 mm | 77% | 2.4 m/s | 2.6 |
| 1992 | 17.3°C | 10.6°C | 3.9°C | 24.2°C | 0.5°C | 59 mm | 50% | 2.3 m/s | 3.3 |
| 1991 | 17.5°C | 10.6°C | 3.8°C | 23.7°C | 0.0°C | 43 mm | 53% | 1.8 m/s | 3.3 |
| 1990 | 17.3°C | 10.7°C | 4.1°C | 27.1°C | -0.9°C | 62 mm | 52% | 2.1 m/s | 3.4 |
| 1989 | 15.6°C | 9.0°C | 2.3°C | 22.3°C | -3.6°C | 24 mm | 51% | 2.5 m/s | 3.3 |
| 1988 | 16.2°C | 9.8°C | 3.3°C | 22.7°C | -2.0°C | 56 mm | 57% | 2.2 m/s | 3 |
| 1987 | 15.9°C | 9.3°C | 2.8°C | 25.7°C | -3.9°C | 52 mm | 53% | 2.4 m/s | 3.2 |
| 1986 | 20.7°C | 13.9°C | 7.1°C | 26.0°C | 4.1°C | 47 mm | 56% | 1.8 m/s | 3 |
| 1985 | 14.9°C | 8.8°C | 2.7°C | 21.8°C | -3.5°C | 25 mm | 62% | 2.2 m/s | 3.2 |
| 1984 | 17.9°C | 11.2°C | 4.5°C | 23.9°C | 0.0°C | 4 mm | 52% | 2.6 m/s | 3.2 |
| 1983 | 17.3°C | 11.0°C | 4.7°C | 24.5°C | -1.0°C | 105 mm | 60% | 2.1 m/s | — |
| 1982 ❄️ | 15.1°C | 8.6°C | 2.1°C | 24.1°C | -3.7°C | 94 mm | 58% | 2.4 m/s | — |
| 1981 | 18.3°C | 12.3°C | 6.2°C | 24.3°C | -2.3°C | 56 mm | 53% | 1.9 m/s | — |
Actual recorded January data for each year, 1981–2025 — sourced from NASA POWER.
The average high in January is around 17.5°C with lows near 5°C (mean 11.3°C), based on 45 years of NASA POWER data.
January averages 67 mm of rainfall in Riverside, a relatively wet time of year. The wettest on record was 348 mm in 1993.
The hottest January reached 30°C in 2003. The coldest dipped to -4.3°C in 2007.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average January temperatures have risen by about 0.9°C. Daytime highs moved from 16.7°C to 17.4°C and overnight lows from 4°C to 5.2°C over the same span.
January is one of the cooler months of the year in Riverside and a relatively wet time of year, so plan for around 17.5°C daytime highs and 5°C at night.
Yes — January is the coldest month of the year in Riverside, averaging 11.3°C.
For January in Riverside, pack warm layers and a jacket for chilly mornings, with typical highs of 17.5°C and lows of 5°C. Bring an umbrella or light rain jacket too.
Relative humidity in January averages 57% — moderately humid.
Average wind speed in January is 2 m/s. The windiest January on record averaged 2.6 m/s (1984).
The wettest January on record was 1993 with 348 mm. On average, January sees 67 mm.
All figures are derived from NASA POWER (Prediction Of Worldwide Energy Resources), based on MERRA-2 satellite reanalysis, covering 1981–2025.
Explore how the weather in Riverside behaves each January, based on 45 years of NASA POWER climate data from 1981 to 2025. This page breaks down average temperatures, rainfall, humidity, wind and solar radiation for January specifically, along with year-by-year records and how the month has changed over the decades.
