What Is the Weather in San Francisco in January?

This post summarizes the San Francisco weather in January, with tips on how to dress and things to do.  January is a relatively mild month for San Francisco, especially when compared to other U.S. cities.  You may find our weather in December post also helpful.

How Much Sun + Rain
What to Wear
Things to Do 




San Francisco during January tends to be on the cool side, but quite mild when compared to most of the rest of the United States during mid-winter. Daytime highs tend to be in the mid-50s F (13-14C) as the new year begins, warming into the upper 50s F (15C) by month’s end.  A few of the warmer days, especially near the end of the month will, sometimes, reach or exceed 65 F (18C).  Overnight lows tend to average in the mid-40s F (7-8C) with a couple of the colder mornings dipping down into the upper 30s F (3-4C).  The warmest temperature ever reported in January was 79F (26.1C) while the coldest was 30 F (-1.1C).


Average temperatures San Francisco January


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Skies over San Francisco during January tend to be sunny or at least partly sunny on about 16 days with cloudy or mostly cloudy conditions on 15 days. Some rainfall occurs on about 11 days this month; however, rainfalls of at least 0.04 inches (1 mm) occur on about 8 days.  Heavy rains of ½ inch (13 mm) or more occur only on about 3 days during this month.


Sun and Rain San Francisco January


Wind speed average around 8-9 mph (13-14 kph) during January, ranging mostly between 4mph and 15 mph (6-24 kph).  Daylight increases during the course of the month from a little over 9 and a half hours on New Year‘s Day to over 10 hours by month’s end.


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So, what should you pack for a January visit to San Francisco?  We would recommend bringing a sweater or sweatshirt in addition to a light to medium weight jacket to wear while exploring the city. On the colder and windier days, it will be helpful to have multiple warm layers in addition to the jacket. The wind near the waterfront tends to be somewhat stronger so dress accordingly and remember to bring a good pair of walking shoes.


Fred Pickhardt

Ocean Weather Services