San Francisco Weather in January
United States · Mediterranean climate · Data averaged from 2020-01-01 to 2024-12-31 (5 years)
January in San Francisco sees average temperatures ranging from a low of 7.9°C (46.2°F) to a high of 13.5°C (56.3°F), with a mean of 10.5°C (50.9°F). Compared to the annual average of 13.5°C (56.3°F), this month is 3.0°C cooler than the yearly norm. This is the coldest month of the year, with average lows of 7.9°C (46.2°F). Precipitation averages 109.2mm, making it approximately 60.0mm wetter than the monthly average of 49.0mm. The city receives an average of 7.0 hours of sunshine per day during January, with relative humidity averaging 82.8%. Wind speeds reach an average maximum of 23.4 km/h. For travelers, this month offers a coldest month of the year experience in San Francisco, with wetter-than-average conditions compared to the rest of the year.
If you're planning outdoor activities in San Francisco, ignore the season — focus on the hour. I hiked Lands End in July at 2pm in a t-shirt and was shivering by 4pm when the fog rolled in. The 5°C temperature swing between coast and bay is real. Best running conditions: September-October, when the marine layer retreats and 22°C hits the city. Pack a windbreaker for any coastal trail, year-round. Marin Headlands is magnificent but windy; aim for 10am-2pm. February-March brings surprisingly green hills and empty trails — my favorite hiking window.
January vs Adjacent Months
| Metric | December | January | February |
|---|---|---|---|
| Mean Temp | 10.5°C (50.9°F) | 10.5°C (50.9°F) | 10.7°C (51.3°F) |
| Rainfall | 174.1mm | 109.2mm | 60.8mm |
| Sunshine | 6.4 hrs | 7.0 hrs | 9.1 hrs |
| Humidity | 83.3% | 82.8% | 77.6% |
| Wind | 21.0 km/h | 23.4 km/h | 24.9 km/h |
| Rainy Days | 14.0 | 13.0 | 8.0 |
Seasonal Context
January falls in Winter in the Northern Hemisphere. Winter is the coolest season with the shortest daylight hours. For travelers visiting San Francisco in January, the data indicates mixed conditions based on the combination of temperature, precipitation, and daylight hours.
Frequently Asked Questions
What is the average temperature in San Francisco in January?
The average temperature in San Francisco during January ranges from 7.9°C (46.2°F) to 13.5°C (56.3°F), with a mean of 10.5°C (50.9°F).
How much does it rain in San Francisco in January?
San Francisco receives an average of 109.2mm of precipitation in January, spread across approximately 13.0 rainy days.
What should I pack for San Francisco in January?
Based on January weather data, pack warm layers, a medium jacket, and waterproof outerwear. Rain gear is essential — this month averages 109.2mm of precipitation.
Is January a good time to visit San Francisco?
January is a cooler month, suitable for travelers who prefer mild weather and fewer crowds. Pack warm layers and enjoy indoor attractions.
Other Months for San Francisco
Cities with Similar January Climate (Mediterranean)
Data Source: Open-Meteo historical archive (2020-01-01 to 2024-12-31). Daily measurements aggregated into monthly climate normals. Coordinates: 37.77°, -122.42°. Timezone: America/Los_Angeles. Last updated: 2026-07-30.