São Martinho Weather in December

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

Average highs run from 19°C on December 1 to 18°C on December 31, and lows from 17°C to 16°C. Normal precipitation for the month is 56 mm over about 9 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: 19°C
Average low: 17°C
Precipitation: 56 mm
Reanalysis high: 21°CDec 5, 2018
Reanalysis low: 13°CDec 18, 2007
Daylight: 10 h 10 min to 10 h 02 min
Cloud cover: 60%
Humidity: 78%
Dew point: 14°C
Wind: 21.6 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	19°C	17°C	21°C 2015	15°C 1999	34%
Dec 2	19°C	17°C	21°C 2016	15°C 2008	34%
Dec 3	19°C	17°C	20°C 1992	15°C 2008	34%
Dec 4	19°C	17°C	21°C 2010	15°C 2003	34%
Dec 5	19°C	17°C	21°C 2018	15°C 2003	32%
Dec 6	19°C	17°C	20°C 2018	15°C 2014	31%
Dec 7	19°C	17°C	21°C 1994	16°C 1999	31%
Dec 8	19°C	17°C	20°C 1997	16°C 1999	31%
Dec 9	19°C	17°C	21°C 2015	15°C 1995	31%
Dec 10	19°C	17°C	20°C 1997	15°C 1995	31%
Dec 11	19°C	17°C	20°C 2009	15°C 1995	32%
Dec 12	19°C	17°C	20°C 1996	15°C 1995	33%
Dec 13	19°C	17°C	21°C 2000	15°C 2014	35%
Dec 14	19°C	17°C	20°C 1997	14°C 2014	36%
Dec 15	19°C	17°C	21°C 2009	15°C 1993	36%
Dec 16	19°C	17°C	21°C 2015	15°C 1993	36%
Dec 17	19°C	17°C	21°C 2015	15°C 2008	36%
Dec 18	19°C	17°C	21°C 2015	13°C 2007	36%
Dec 19	19°C	17°C	20°C 2019	14°C 2000	36%
Dec 20	18°C	17°C	21°C 2019	15°C 2000	36%
Dec 21	18°C	17°C	21°C 2019	15°C 2008	36%
Dec 22	18°C	17°C	21°C 2019	15°C 2008	35%
Dec 23	18°C	17°C	21°C 2009	14°C 1993	35%
Dec 24	18°C	17°C	20°C 2009	15°C 2004	35%
Dec 25	18°C	17°C	20°C 2019	15°C 1993	35%
Dec 26	18°C	17°C	20°C 2019	15°C 1993	34%
Dec 27	18°C	17°C	21°C 2019	14°C 2014	32%
Dec 28	18°C	17°C	21°C 2009	15°C 2014	31%
Dec 29	18°C	16°C	21°C 2019	14°C 2013	30%
Dec 30	18°C	16°C	21°C 2019	14°C 2013	31%
Dec 31	18°C	16°C	21°C 1994	14°C 1992	30%

Chance of rain

Chance of a wet day

Sunrise and sunset

Times for 2026, local time (GMT+0).

December 1: sunrise 7:52 AM, sunset 6:02 PM
December 31: sunrise 8:10 AM, sunset 6:12 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 2026-09-24. Sun and moon: computed with the NOAA solar equations and Meeus.