Santa Helena Weather in December

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

Average highs run from 36°C on December 1 to 34°C on December 31, and lows from 24°C to 24°C. Normal precipitation for the month is 53 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: 35°C
Average low: 24°C
Precipitation: 53 mm
Reanalysis high: 39°CDec 7, 2003
Reanalysis low: 20°CDec 23, 1998
Daylight: 12 h 15 min to 12 h 15 min
Cloud cover: 59%
Humidity: 67%
Dew point: 21°C
Wind: 6.1 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	36°C	24°C	38°C 2015	23°C 2012	15%
Dec 2	36°C	24°C	38°C 1998	22°C 1991	16%
Dec 3	36°C	24°C	39°C 1997	23°C 2006	16%
Dec 4	36°C	24°C	38°C 2003	21°C 1994	16%
Dec 5	36°C	24°C	39°C 1998	21°C 1996	18%
Dec 6	36°C	24°C	38°C 2005	22°C 1995	20%
Dec 7	36°C	24°C	39°C 2003	21°C 1995	20%
Dec 8	36°C	24°C	38°C 2016	22°C 1995	21%
Dec 9	36°C	24°C	38°C 2006	23°C 1998	23%
Dec 10	36°C	24°C	38°C 2017	23°C 2010	23%
Dec 11	36°C	24°C	38°C 2017	23°C 2018	24%
Dec 12	36°C	24°C	38°C 2017	22°C 1991	25%
Dec 13	36°C	24°C	38°C 1998	23°C 2005	26%
Dec 14	36°C	24°C	37°C 2006	22°C 2010	28%
Dec 15	35°C	24°C	38°C 2012	23°C 2000	29%
Dec 16	35°C	24°C	38°C 1991	22°C 2000	31%
Dec 17	35°C	24°C	38°C 2005	22°C 2000	32%
Dec 18	35°C	24°C	38°C 1999	22°C 2000	34%
Dec 19	35°C	24°C	38°C 1991	22°C 2010	36%
Dec 20	35°C	24°C	38°C 1996	21°C 2016	36%
Dec 21	35°C	24°C	37°C 2014	21°C 2000	36%
Dec 22	35°C	24°C	37°C 1991	21°C 2000	37%
Dec 23	35°C	24°C	38°C 2003	20°C 1998	37%
Dec 24	35°C	24°C	38°C 2003	22°C 2004	38%
Dec 25	35°C	24°C	38°C 2013	22°C 2018	41%
Dec 26	35°C	24°C	38°C 1997	22°C 2000	43%
Dec 27	34°C	24°C	38°C 2008	21°C 2018	44%
Dec 28	34°C	24°C	37°C 2017	22°C 2005	45%
Dec 29	34°C	24°C	37°C 2011	21°C 2005	46%
Dec 30	34°C	24°C	38°C 2002	22°C 1999	47%
Dec 31	34°C	24°C	37°C 1996	22°C 1999	49%

Chance of rain

Chance of a wet day

Sunrise and sunset

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

December 1: sunrise 5:43 AM, sunset 5:58 PM
December 31: sunrise 5:57 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 2026-09-25. Sun and moon: computed with the NOAA solar equations and Meeus.