San Francisco weather in January
January in San Francisco: cool, rainy, with clean air — a great time to visit.
#11 of 12 months in San Francisco · #279 of 604 destinations to visit in January · comfort 71/100 (tier B)
Updated June 2026 · climate normals from ERA5 reanalysis
San Francisco climate normals — January
| Daytime high | 14°C / 58°F | 🙂 cool |
|---|---|---|
| Nighttime low | 7°C / 45°F | |
| Feels like (high) | 13°C / 55°F | |
| Rainfall | 89 mm / 3.5 in | 🌧 rainy |
| Rainy days | 8 days | |
| Humidity | 81% | 💦 very humid |
| Dew point | 7°C / 44°F | |
| Sunshine | 7 h/day | |
| Daylight | 9.9 h | |
| Wind | 15 km/h / 9 mph | |
| Air quality (US AQI) | 45 | 🍃 good |
Monthly averages from ERA5 reanalysis. AQI is the mean US Air Quality Index for the month.
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San Francisco in January — FAQ
- Is January a good time to visit San Francisco?
- January in San Francisco: cool, rainy, with clean air — a great time to visit. It ranks #11 of 12 months for San Francisco on SeasonMap's comfort score (71/100).
- What is the weather like in San Francisco in January?
- In January, San Francisco averages a daily high of 14.4°C and a low of 7°C, with about 88.6 mm of rain over roughly 8.2 rainy days.
- What is the air quality in San Francisco in January?
- San Francisco has a mean US Air Quality Index of about 45 in January.