Is San Francisco hot in January?
Days are typically cool at 14.7°C, while nights average 8.3°C.
United States · 1991–2020 normal
Typical January weather in San Francisco: 14.7°C by day, 8.3°C at night, 112 mm of rain over 9.6 wet days. These are measured 1991–2020 station normals, not a forecast.
In the year-round weather comparison, January scores 40 out of 100 (September leads the year at 89). Daylight is calculated as 9 h 49 from latitude 37.77°. Open-water sea temperature is 11.6°C (21 km from the place centre).
January at a glance
Plain answers from the measured climate record—not a forecast or a promise about a particular trip.
Days are typically cool at 14.7°C, while nights average 8.3°C.
The measured monthly average is 112 mm across about 10 wet days.
There are about 9 h 49 between sunrise and sunset at mid-month, calculated from the place latitude.
January ranks 11 of 12 in our weather comparison; September ranks first.
The evidence behind this page
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The weather comparison for San Francisco is based on climate evidence, not payments from travel companies. Flight, accommodation and activity links will be clearly labelled when they are added; there are no booking offers on this page today.
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