Castelo Weather in December

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

Average highs run from 27°C on December 1 to 28°C on December 31, and lows from 18°C to 19°C. Normal precipitation for the month is 239 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: 28°C
Average low: 19°C
Precipitation: 239 mm
Reanalysis high: 37°CDec 29, 2014
Reanalysis low: 13°CDec 4, 2005
Daylight: 13 h 18 min to 13 h 22 min
Cloud cover: 72%
Humidity: 83%
Dew point: 19°C
Wind: 14.0 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	27°C	18°C	34°C 1993	16°C 1996	75%
Dec 2	27°C	18°C	34°C 2002	16°C 2016	75%
Dec 3	27°C	19°C	32°C 2007	15°C 2001	76%
Dec 4	27°C	19°C	32°C 2007	13°C 2005	76%
Dec 5	27°C	19°C	32°C 2002	13°C 2005	77%
Dec 6	27°C	19°C	32°C 2007	15°C 1992	78%
Dec 7	27°C	19°C	32°C 1993	16°C 2005	78%
Dec 8	27°C	19°C	34°C 2012	14°C 2000	78%
Dec 9	27°C	19°C	30°C 2012	13°C 2018	77%
Dec 10	27°C	19°C	30°C 2013	15°C 1996	76%
Dec 11	27°C	19°C	31°C 2007	15°C 1995	76%
Dec 12	27°C	19°C	31°C 2007	16°C 2011	76%
Dec 13	27°C	19°C	31°C 2009	15°C 1992	76%
Dec 14	28°C	19°C	32°C 2015	14°C 1992	75%
Dec 15	28°C	19°C	32°C 2015	14°C 1992	74%
Dec 16	28°C	19°C	33°C 2015	16°C 2014	72%
Dec 17	28°C	19°C	32°C 2012	15°C 2014	72%
Dec 18	28°C	19°C	34°C 2018	18°C 1999	72%
Dec 19	28°C	19°C	35°C 2018	17°C 2016	72%
Dec 20	28°C	19°C	34°C 2018	17°C 2008	72%
Dec 21	28°C	19°C	35°C 2018	17°C 2017	72%
Dec 22	28°C	19°C	35°C 2018	17°C 1993	71%
Dec 23	28°C	19°C	35°C 2018	16°C 1993	70%
Dec 24	28°C	19°C	34°C 2015	16°C 1992	70%
Dec 25	28°C	19°C	34°C 2012	16°C 1992	70%
Dec 26	28°C	19°C	35°C 2012	16°C 2005	70%
Dec 27	28°C	19°C	34°C 2012	16°C 2005	70%
Dec 28	28°C	19°C	36°C 2014	17°C 2005	69%
Dec 29	28°C	19°C	37°C 2014	17°C 2019	68%
Dec 30	28°C	19°C	36°C 2014	17°C 2011	68%
Dec 31	28°C	19°C	35°C 2014	17°C 1992	67%

Chance of rain

Chance of a wet day

Sunrise and sunset

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

December 1: sunrise 4:55 AM, sunset 6:13 PM
December 31: sunrise 5:07 AM, sunset 6:29 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.