January is one of the cooler months of the year in San Francisco, with average highs near 13.5°C and lows around 6.3°C (mean 9.9°C). It is a relatively wet time of year, averaging 116 mm of rainfall and 84% relative humidity across the period.
January is one of the cooler months of the year in San Francisco. Across 45 years of records, the warmest Januarys in San Francisco were 2003 and 2014 — when the month averaged 11.8°C — while the coldest was 1982 at 7.5°C. Typical January days reach 13.5°C with nights near 6.3°C. The long-term trend is warming, about 0.2°C per decade.
January is a relatively wet time of year in San Francisco, averaging 116 mm of rainfall. The wettest January on record was 1995 with 337 mm, while the driest was 2015 at 1 mm.
Relative humidity in San Francisco during January averages 84%. The most humid January was 2003 at 91%, and the least humid was 2014 at 66%.
January receives about 2.4 kWh/m²/day of solar energy in San Francisco. The sunniest Januarys were 2007 and 2013 at 2.9 kWh/m²/day, and the cloudiest was 1995 at 1.9.
Average wind speed in San Francisco during January is 2.2 m/s. The windiest January was 1995 at 3.1 m/s, while the calmest were 2003 and 2015 at 1.6 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 9.5°C | 10.1°C | 9.4°C | 10.2°C | 10.5°C | +1°C |
| Avg High | 13.3°C | 13.6°C | 13.0°C | 13.8°C | 14.1°C | +0.8°C |
| Avg Low | 5.7°C | 6.6°C | 5.9°C | 6.5°C | 7.0°C | +1.3°C |
| Avg Rain | 111 mm | 155 mm | 99 mm | 113 mm | 91 mm | -20 mm |
January temperatures in San Francisco have risen by about 1.1°C between 1981–1985 and 2021–2025.
January has ranged from a record low of -0.8°C (1997) to a record high of 22.2°C (2021).
Rainfall in January is a relatively wet time of year, averaging 116 mm, with a wettest year of 337 mm.
A quieter season to visit San Francisco
If your dates are flexible, the more temperate months of September and August tend to be the most comfortable for visiting San Francisco. That said, January — with days averaging 13.5°C and nights around 6.3°C (mean 9.9°C) and higher rainfall (116 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 | 14.3°C | 10.2°C | 6.1°C | 17.5°C | 3.3°C | 15 mm | 83% | 1.8 m/s | 2.8 |
| 2024 | 14.4°C | 11.3°C | 8.3°C | 19.6°C | 3.9°C | 149 mm | 90% | 2.2 m/s | 2.2 |
| 2023 | 12.9°C | 9.8°C | 6.8°C | 15.9°C | 1.6°C | 247 mm | 84% | 2.9 m/s | 2.4 |
| 2022 | 14.5°C | 10.4°C | 6.3°C | 16.6°C | 0.8°C | 8 mm | 85% | 1.8 m/s | 2.7 |
| 2021 | 14.6°C | 10.9°C | 7.2°C | 22.2°C | 2.7°C | 80 mm | 81% | 2 m/s | 2.5 |
| 2020 | 13.7°C | 10.4°C | 7.1°C | 18.7°C | 4.5°C | 46 mm | 89% | 2 m/s | 2.4 |
| 2019 | 14.4°C | 11.2°C | 7.9°C | 17.7°C | 2.5°C | 145 mm | 84% | 2.2 m/s | 2.2 |
| 2018 | 14.4°C | 11.2°C | 8.0°C | 18.3°C | 4.5°C | 133 mm | 88% | 1.8 m/s | 2.2 |
| 2017 | 11.8°C | 8.6°C | 5.5°C | 14.6°C | -0.5°C | 303 mm | 87% | 2.7 m/s | 2.4 |
| 2016 | 13.3°C | 10.6°C | 8.0°C | 16.1°C | 0.4°C | 177 mm | 88% | 2.3 m/s | 2 |
| 2015 | 15.1°C | 11.2°C | 7.3°C | 18.8°C | 1.5°C | 1 mm | 85% | 1.6 m/s | 2.8 |
| 2014 | 16.8°C | 11.8°C | 6.8°C | 21.0°C | 4.7°C | 3 mm | 66% | 1.7 m/s | 2.8 |
| 2013 | 12.4°C | 8.1°C | 3.9°C | 17.2°C | -0.7°C | 18 mm | 83% | 2.2 m/s | 2.9 |
| 2012 | 14.3°C | 9.9°C | 5.5°C | 18.4°C | 1.4°C | 98 mm | 78% | 2.1 m/s | 2.6 |
| 2011 | 13.2°C | 9.2°C | 5.3°C | 17.0°C | 0.6°C | 37 mm | 87% | 1.9 m/s | 2.5 |
| 2010 | 12.6°C | 9.8°C | 7.0°C | 14.6°C | 4.1°C | 212 mm | 90% | 2.3 m/s | 2 |
| 2009 | 14.7°C | 10.0°C | 5.4°C | 20.0°C | 0.1°C | 30 mm | 76% | 2 m/s | 2.7 |
| 2008 | 11.1°C | 8.2°C | 5.3°C | 14.8°C | 2.6°C | 246 mm | 87% | 2.7 m/s | 2 |
| 2007 | 12.4°C | 8.2°C | 4.1°C | 16.3°C | -0.7°C | 12 mm | 78% | 2.1 m/s | 2.9 |
| 2006 | 13.0°C | 9.8°C | 6.6°C | 15.9°C | 3.9°C | 110 mm | 89% | 2.2 m/s | 2.5 |
| 2005 | 12.8°C | 9.4°C | 6.1°C | 16.2°C | 1.4°C | 118 mm | 86% | 2.2 m/s | 2.4 |
| 2004 | 12.5°C | 9.4°C | 6.4°C | 15.9°C | 1.8°C | 79 mm | 88% | 2.1 m/s | 2.2 |
| 2003 🔥 | 14.9°C | 11.8°C | 8.7°C | 18.8°C | 5.0°C | 66 mm | 91% | 1.6 m/s | 2.3 |
| 2002 | 12.0°C | 8.5°C | 4.9°C | 15.1°C | 0.3°C | 67 mm | 85% | 2 m/s | 2.6 |
| 2001 | 13.1°C | 9.0°C | 4.9°C | 17.3°C | 1.4°C | 105 mm | 78% | 2.4 m/s | 2.6 |
| 2000 | 13.0°C | 10.0°C | 6.9°C | 15.5°C | 2.2°C | 154 mm | 88% | 2 m/s | 2.1 |
| 1999 | 13.1°C | 9.3°C | 5.5°C | 15.3°C | 2.1°C | 93 mm | 84% | 2.1 m/s | 2.4 |
| 1998 | 13.6°C | 11.2°C | 8.9°C | 17.3°C | 3.9°C | 232 mm | 90% | 2.4 m/s | 2 |
| 1997 | 13.1°C | 10.1°C | 7.0°C | 16.6°C | -0.8°C | 192 mm | 87% | 2.2 m/s | 2.2 |
| 1996 | 13.7°C | 10.5°C | 7.2°C | 16.7°C | 4.0°C | 172 mm | 86% | 2.3 m/s | 2.2 |
| 1995 🌧️ | 13.0°C | 10.9°C | 8.8°C | 18.9°C | 4.1°C | 337 mm | 90% | 3.1 m/s | 1.9 |
| 1994 | 14.6°C | 10.3°C | 6.0°C | 19.1°C | 2.4°C | 59 mm | 82% | 2 m/s | 2.7 |
| 1993 | 12.4°C | 8.9°C | 5.4°C | 15.5°C | 0.4°C | 253 mm | 84% | 2.7 m/s | 2.3 |
| 1992 | 13.9°C | 9.7°C | 5.6°C | 16.1°C | 2.6°C | 78 mm | 82% | 2.1 m/s | 2.7 |
| 1991 | 14.8°C | 10.1°C | 5.4°C | 20.4°C | 1.9°C | 16 mm | 75% | 1.8 m/s | 2.5 |
| 1990 | 13.9°C | 10.0°C | 6.1°C | 16.7°C | 1.9°C | 111 mm | 83% | 2.4 m/s | 2.7 |
| 1989 | 12.8°C | 8.4°C | 4.0°C | 17.3°C | 0.9°C | 32 mm | 82% | 2.1 m/s | 2.7 |
| 1988 | 12.7°C | 9.5°C | 6.2°C | 16.9°C | 1.8°C | 130 mm | 85% | 2.3 m/s | 2.2 |
| 1987 | 12.9°C | 9.0°C | 5.1°C | 18.2°C | 0.7°C | 90 mm | 78% | 2.3 m/s | 2.5 |
| 1986 | 14.8°C | 11.6°C | 8.4°C | 17.1°C | 4.4°C | 140 mm | 84% | 2.1 m/s | 2.1 |
| 1985 | 12.9°C | 8.5°C | 4.2°C | 16.5°C | 0.5°C | 32 mm | 81% | 1.8 m/s | 2.6 |
| 1984 | 13.5°C | 9.6°C | 5.7°C | 18.2°C | 1.7°C | 12 mm | 86% | 1.9 m/s | 2.5 |
| 1983 | 13.9°C | 10.2°C | 6.5°C | 16.5°C | 0.8°C | 206 mm | 84% | 2.6 m/s | — |
| 1982 ❄️ | 11.1°C | 7.5°C | 3.8°C | 14.7°C | -0.7°C | 209 mm | 84% | 2.5 m/s | — |
| 1981 | 14.9°C | 11.1°C | 7.3°C | 18.6°C | 1.9°C | 151 mm | 80% | 2.4 m/s | — |
Actual recorded January data for each year, 1981–2025 — sourced from NASA POWER.
The average high in January is around 13.5°C with lows near 6.3°C (mean 9.9°C), based on 45 years of NASA POWER data.
January averages 116 mm of rainfall in San Francisco, a relatively wet time of year. The wettest on record was 337 mm in 1995.
The hottest January reached 22.2°C in 2021. The coldest dipped to -0.8°C in 1997.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average January temperatures have risen by about 1.1°C. Daytime highs moved from 13.3°C to 14.1°C and overnight lows from 5.5°C to 6.9°C over the same span.
January is one of the cooler months of the year in San Francisco and a relatively wet time of year, so plan for around 13.5°C daytime highs and 6.3°C at night.
Yes — January is the coldest month of the year in San Francisco, averaging 9.9°C.
For January in San Francisco, pack warm layers and a jacket for chilly mornings, with typical highs of 13.5°C and lows of 6.3°C. Bring an umbrella or light rain jacket too.
Relative humidity in January averages 84% — quite humid.
Average wind speed in January is 2.2 m/s. The windiest January on record averaged 3.1 m/s (1995).
The wettest January on record was 1995 with 337 mm. On average, January sees 116 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 San Francisco 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.
