San Francisco Weather in January

NASA POWER reanalysis for the half-degree grid cell around San Francisco, 1991-2020; a grid cell is an area average and can differ from a thermometer in town by several degrees

Average highs run from 33°C on January 1 to 33°C on January 31, and lows from 19°C to 19°C. Normal precipitation for the month is 118 mm over about 12 wet days.

January day by day

The normal high and low for each date, in °C.

Normal low
Normal high
Reanalysis extreme high
Reanalysis extreme low

January at a glance

Average high: 33°C
Average low: 19°C
Precipitation: 118 mm
Reanalysis high: 43°CJan 9, 2006
Reanalysis low: 10°CJan 11, 2001
Daylight: 14 h 09 min to 13 h 36 min
Cloud cover: 54%
Humidity: 59%
Dew point: 16°C
Wind: 13.3 km/h

Every day of the month

A wet day has at least 1 mm of precipitation in the reanalysis.

Date	Normal high	Normal low	Reanalysis high	Reanalysis low	Chance wet
Jan 1	33°C	19°C	40°C 1995	13°C 2004	42%
Jan 2	34°C	20°C	41°C 1996	11°C 2015	43%
Jan 3	33°C	20°C	40°C 2012	12°C 2015	44%
Jan 4	33°C	19°C	40°C 2018	14°C 2014	44%
Jan 5	33°C	19°C	40°C 2006	15°C 1996	44%
Jan 6	33°C	19°C	42°C 2006	14°C 2002	42%
Jan 7	33°C	19°C	42°C 2006	13°C 2010	42%
Jan 8	33°C	19°C	42°C 2006	13°C 1998	42%
Jan 9	33°C	19°C	43°C 2006	13°C 1993	41%
Jan 10	33°C	19°C	40°C 2018	13°C 1995	40%
Jan 11	33°C	19°C	40°C 2018	10°C 2001	39%
Jan 12	33°C	19°C	40°C 2002	11°C 2001	39%
Jan 13	33°C	19°C	39°C 2002	13°C 2010	38%
Jan 14	33°C	19°C	41°C 2011	14°C 2012	37%
Jan 15	33°C	19°C	41°C 2011	12°C 2002	37%
Jan 16	33°C	19°C	40°C 2014	11°C 1992	37%
Jan 17	33°C	19°C	40°C 2014	12°C 1991	37%
Jan 18	33°C	19°C	42°C 2014	13°C 2006	36%
Jan 19	33°C	19°C	41°C 2016	12°C 2009	35%
Jan 20	33°C	19°C	42°C 2016	14°C 2019	35%
Jan 21	33°C	19°C	42°C 2016	14°C 2005	35%
Jan 22	33°C	19°C	43°C 2014	14°C 1991	36%
Jan 23	33°C	19°C	42°C 2016	13°C 2003	35%
Jan 24	34°C	19°C	42°C 2016	13°C 2003	37%
Jan 25	34°C	19°C	38°C 1997	14°C 2005	38%
Jan 26	33°C	19°C	40°C 1997	14°C 2013	39%
Jan 27	33°C	19°C	40°C 1997	13°C 2017	39%
Jan 28	33°C	19°C	40°C 2004	15°C 1998	40%
Jan 29	33°C	19°C	41°C 2004	13°C 1998	42%
Jan 30	33°C	19°C	42°C 2004	13°C 1991	42%
Jan 31	33°C	19°C	42°C 2003	14°C 2005	43%

Chance of rain

Chance of a wet day

Sunrise and sunset

Times for 2026, local time (GMT-3).

January 1: sunrise 6:07 AM, sunset 8:16 PM
January 31: sunrise 6:34 AM, sunset 8:10 PM

Every day of January: sun and moon

Other months

Sources

Cloud, humidity, wind and sunshine, and temperature and precipitation: NASA POWER (MERRA-2, CERES and GEWEX SRB), 1991-2020. The data was obtained from the National Aeronautics and Space Administration (NASA) Langley Research Center's Prediction Of Worldwide Energy Resources (POWER) project funded through the NASA Earth Science Division: POWER Daily API v2, accessed 2026-09-25. Sun and moon: computed with the NOAA solar equations and Meeus.