Castro Weather in December

NASA POWER reanalysis for the half-degree grid cell around Castro, 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 16°C to 17°C. Normal precipitation for the month is 155 mm over about 19 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: 16°C
Precipitation: 155 mm
Reanalysis high: 35°CDec 29, 2019
Reanalysis low: 9°CDec 2, 2001
Daylight: 13 h 34 min to 13 h 40 min
Cloud cover: 75%
Humidity: 79%
Dew point: 17°C
Wind: 5.8 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	16°C	32°C 2007	10°C 1994	55%
Dec 2	27°C	16°C	33°C 2007	9°C 2001	55%
Dec 3	27°C	16°C	31°C 2003	11°C 2011	55%
Dec 4	27°C	16°C	33°C 2012	9°C 2008	55%
Dec 5	27°C	16°C	32°C 2012	12°C 2008	56%
Dec 6	27°C	16°C	31°C 1991	12°C 2018	56%
Dec 7	27°C	16°C	32°C 2012	13°C 2001	57%
Dec 8	27°C	16°C	34°C 2012	11°C 2018	57%
Dec 9	27°C	16°C	33°C 2008	10°C 2018	58%
Dec 10	27°C	16°C	32°C 2012	10°C 2003	59%
Dec 11	27°C	16°C	32°C 2012	13°C 2004	58%
Dec 12	27°C	16°C	32°C 2018	12°C 2004	57%
Dec 13	27°C	16°C	32°C 2018	12°C 2007	57%
Dec 14	28°C	16°C	32°C 2018	10°C 2010	58%
Dec 15	28°C	16°C	34°C 2018	11°C 1995	59%
Dec 16	27°C	16°C	34°C 2006	12°C 2016	60%
Dec 17	27°C	16°C	34°C 2018	12°C 2011	60%
Dec 18	28°C	16°C	32°C 2006	11°C 2000	62%
Dec 19	28°C	17°C	32°C 2018	11°C 2000	61%
Dec 20	28°C	17°C	32°C 2018	14°C 2008	61%
Dec 21	28°C	17°C	33°C 1999	13°C 1993	62%
Dec 22	28°C	17°C	33°C 2008	12°C 1993	62%
Dec 23	28°C	17°C	33°C 2008	13°C 2004	62%
Dec 24	28°C	17°C	33°C 2012	13°C 2003	63%
Dec 25	28°C	17°C	32°C 2012	12°C 2003	64%
Dec 26	28°C	17°C	33°C 2019	13°C 2001	67%
Dec 27	28°C	17°C	33°C 2019	13°C 2008	68%
Dec 28	28°C	17°C	34°C 2019	11°C 1991	68%
Dec 29	28°C	17°C	35°C 2019	13°C 1992	68%
Dec 30	28°C	17°C	35°C 2019	14°C 1993	68%
Dec 31	28°C	17°C	34°C 2019	12°C 1993	68%

Chance of rain

Chance of a wet day

Sunrise and sunset

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

December 1: sunrise 5:22 AM, sunset 6:56 PM
December 31: sunrise 5:33 AM, sunset 7:13 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.