São Francisco Weather in December

NASA POWER reanalysis for the half-degree grid cell around São 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 30°C on December 1 to 30°C on December 31, and lows from 21°C to 21°C. Normal precipitation for the month is 205 mm over about 22 wet days.

December day by day

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

Normal low
Normal high
Reanalysis extreme high
Reanalysis extreme low

December at a glance

Average high: 30°C
Average low: 21°C
Precipitation: 205 mm
Reanalysis high: 40°CDec 22, 2019
Reanalysis low: 17°CDec 3, 2014
Daylight: 13 h 01 min to 13 h 03 min
Cloud cover: 72%
Humidity: 75%
Dew point: 20°C
Wind: 10.1 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
Dec 1	30°C	21°C	37°C 2002	17°C 1996	71%
Dec 2	30°C	21°C	38°C 2002	18°C 1995	72%
Dec 3	30°C	21°C	39°C 2002	17°C 2014	72%
Dec 4	30°C	21°C	39°C 2002	18°C 2014	71%
Dec 5	30°C	21°C	39°C 2002	18°C 2004	71%
Dec 6	30°C	21°C	38°C 2002	18°C 1992	71%
Dec 7	30°C	21°C	36°C 1993	19°C 2012	70%
Dec 8	30°C	21°C	35°C 1993	19°C 2014	70%
Dec 9	30°C	21°C	35°C 2004	18°C 2018	71%
Dec 10	30°C	21°C	34°C 2001	17°C 1999	70%
Dec 11	30°C	21°C	35°C 2001	18°C 1994	70%
Dec 12	30°C	21°C	36°C 2001	18°C 1994	70%
Dec 13	30°C	21°C	36°C 2003	18°C 1994	69%
Dec 14	30°C	21°C	36°C 2003	17°C 2020	67%
Dec 15	30°C	21°C	36°C 2003	18°C 1992	66%
Dec 16	30°C	21°C	37°C 2003	19°C 2016	64%
Dec 17	30°C	21°C	39°C 2003	18°C 2016	63%
Dec 18	30°C	21°C	37°C 2019	18°C 2018	62%
Dec 19	30°C	21°C	38°C 2019	19°C 1995	61%
Dec 20	30°C	21°C	38°C 2019	18°C 2017	60%
Dec 21	30°C	21°C	39°C 2003	18°C 2005	61%
Dec 22	30°C	21°C	40°C 2019	18°C 2005	61%
Dec 23	30°C	21°C	38°C 2015	17°C 2005	61%
Dec 24	30°C	21°C	38°C 2015	18°C 2006	60%
Dec 25	31°C	21°C	37°C 2012	17°C 1991	60%
Dec 26	30°C	21°C	38°C 2012	18°C 2000	61%
Dec 27	30°C	21°C	39°C 2012	18°C 2007	60%
Dec 28	30°C	21°C	37°C 2012	18°C 1998	61%
Dec 29	31°C	21°C	38°C 2019	18°C 1994	62%
Dec 30	31°C	21°C	38°C 2019	18°C 2005	62%
Dec 31	30°C	21°C	39°C 2019	17°C 1992	62%

Chance of rain

Chance of a wet day

Sunrise and sunset

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

December 1: sunrise 5:18 AM, sunset 6:19 PM
December 31: sunrise 5:31 AM, sunset 6:34 PM

Every day of December: 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.