San Francisco weather in January

January is one of the least pleasant months in San Francisco: highs of 13°C (55°F) and about 100 mm (3.9 in) of rain on average. Nights average 6°C (42°F) and cloud cover 58% (NASA POWER, 2001–2025 averages). The sea averages 13°C (55°F). It is the 3rd wettest month of the year and the coolest. Compared with December, it is about as warm and drier; February brings highs of 14°C (57°F) and 102 mm (4.0 in) of rain.

Is January a good time to visit San Francisco?

least pleasant month Weather score 50/100.

January is one of the least pleasant months for weather in San Francisco. For better conditions, consider May–Oct.

See San Francisco's sky and forecast now

Does it rain a lot in San Francisco in January?

Some rain is normal: about 100 mm (3.9 in) falls in an average January. It is the 3rd wettest month of the year.

How warm is San Francisco in January?

Days average 13°C (55°F) and nights 6°C (42°F).

San Francisco weather by month

Month	High	Low	Rain	Cloud	Sea	Weather
January	13°C (55°F)	6°C (42°F)	100 mm	58%	13°C (55°F)	least pleasant
February	14°C (57°F)	7°C (44°F)	102 mm	58%	13°C (55°F)	least pleasant
March	15°C (60°F)	8°C (46°F)	82 mm	58%	13°C (56°F)	fair
April	17°C (62°F)	8°C (46°F)	42 mm	53%	13°C (56°F)	fair
May	19°C (65°F)	9°C (49°F)	18 mm	51%	13°C (56°F)	best
June	21°C (70°F)	11°C (51°F)	6 mm	44%	14°C (57°F)	best
July	22°C (72°F)	12°C (53°F)	1 mm	56%	15°C (59°F)	best
August	23°C (73°F)	12°C (54°F)	1 mm	57%	15°C (60°F)	best
September	23°C (74°F)	12°C (54°F)	4 mm	46%	17°C (62°F)	best
October	21°C (70°F)	11°C (51°F)	29 mm	44%	16°C (61°F)	best
November	17°C (62°F)	8°C (47°F)	62 mm	50%	14°C (57°F)	fair
December	13°C (56°F)	6°C (43°F)	138 mm	59%	13°C (55°F)	least pleasant

Sources: 2001–2025 monthly averages from NASA POWER (MERRA-2 reanalysis), sea temperature from Open-Meteo Marine. Page updated Oct 31, 2026. How we rate months

Nearby places in January

Los Angeles in January San Diego in January San Jose in January