Chilaw Weather in December

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

Average highs run from 29°C on December 1 to 29°C on December 31, and lows from 24°C to 23°C. Normal precipitation for the month is 145 mm over about 18 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: 29°C
Average low: 23°C
Precipitation: 145 mm
Reanalysis high: 33°CDec 25, 1995
Reanalysis low: 19°CDec 22, 2004
Daylight: 11 h 43 min to 11 h 41 min
Cloud cover: 72%
Humidity: 84%
Dew point: 23°C
Wind: 18.4 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	29°C	24°C	32°C 1995	20°C 1991	66%
Dec 2	29°C	24°C	31°C 1996	21°C 1991	66%
Dec 3	29°C	24°C	31°C 1996	20°C 1991	64%
Dec 4	29°C	24°C	32°C 1995	22°C 1991	63%
Dec 5	29°C	24°C	30°C 1996	22°C 2011	62%
Dec 6	29°C	23°C	31°C 1996	22°C 1991	61%
Dec 7	29°C	23°C	33°C 1995	21°C 1991	61%
Dec 8	29°C	23°C	33°C 1995	21°C 1991	62%
Dec 9	29°C	23°C	32°C 1995	20°C 1991	62%
Dec 10	29°C	23°C	33°C 1995	21°C 1999	62%
Dec 11	29°C	23°C	33°C 1995	21°C 2000	62%
Dec 12	29°C	23°C	32°C 1995	20°C 2018	62%
Dec 13	29°C	23°C	32°C 1995	20°C 1994	61%
Dec 14	29°C	23°C	33°C 1995	21°C 2012	61%
Dec 15	29°C	23°C	33°C 1995	21°C 2001	62%
Dec 16	29°C	23°C	33°C 1995	20°C 2001	62%
Dec 17	29°C	23°C	33°C 1995	21°C 2018	62%
Dec 18	29°C	23°C	33°C 1995	22°C 1998	62%
Dec 19	29°C	23°C	33°C 1995	21°C 2004	61%
Dec 20	29°C	23°C	33°C 1995	20°C 2004	60%
Dec 21	29°C	23°C	33°C 1995	19°C 2004	59%
Dec 22	29°C	23°C	32°C 1995	19°C 2004	58%
Dec 23	29°C	23°C	32°C 1995	20°C 2016	55%
Dec 24	29°C	23°C	32°C 1995	19°C 2016	53%
Dec 25	29°C	23°C	33°C 1995	20°C 2016	50%
Dec 26	29°C	23°C	33°C 1995	19°C 2007	47%
Dec 27	29°C	23°C	33°C 1995	20°C 1992	45%
Dec 28	29°C	23°C	33°C 1995	19°C 2005	43%
Dec 29	29°C	23°C	33°C 1994	19°C 2002	41%
Dec 30	29°C	23°C	32°C 1995	19°C 2006	42%
Dec 31	29°C	23°C	32°C 1996	19°C 2006	40%

Chance of rain

Chance of a wet day

Sunrise and sunset

Times for 2026, local time (GMT+5:30).

December 1: sunrise 6:08 AM, sunset 5:51 PM
December 31: sunrise 6:23 AM, sunset 6:04 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 2026-09-26. Sun and moon: computed with the NOAA solar equations and Meeus.