Chilaw climate — normals and trends

Q: What is the climate of Chilaw?

Chilaw has a tropical monsoon climate (Köppen Am). Over 1940-2025, the average annual temperature is 26.9 °C and it receives 1,871 mm of precipitation per year.

Q: What is the hottest day ever recorded in Chilaw?

The hottest day measured in Chilaw between 1940 and 2025 was 10 March 2010, reaching 34.7 °C.

Q: What is the coldest day in Chilaw?

The coldest day measured in Chilaw between 1940 and 2025 was 22 January 1956, at 20.5 °C.

Q: Does it snow in Chilaw?

Almost never: Chilaw sees virtually no snow, with about 0 frost days per year.

Q: Has the climate of Chilaw warmed?

Yes: Chilaw warmed by +1.4 °C between 1940 and 2025, a statistically significant trend.

Q: What is the wettest day in Chilaw?

The wettest day measured in Chilaw between 1940 and 2025 was 28 November 2025, with 227 mm of rain in 24 hours.

Q: What was the windiest day in Chilaw?

The windiest day measured in Chilaw between 1940 and 2025 was 13 November 1992, with winds reaching 49.7 km/h.

Q: What is the warmest month in Chilaw?

The warmest month in Chilaw is April (27.8 °C on average); the coldest is January (26.1 °C).

Q: How much does it rain in Chilaw?

Chilaw receives on average 1,871 mm of precipitation per year, spread over about 247 rainy days.

Q: Is it sunny in Chilaw?

Chilaw gets on average 10.4 hours of sunshine per day, roughly 3,796 hours per year over 1940-2025.

Chilaw (Sri Lanka) has a tropical monsoon climate (Am) under the Köppen-Geiger classification. Its mean annual temperature is 26.9 °C and it receives 1,871 mm of precipitation per year.

These figures are normals computed over 86 complete calendar years, from 1940 to 2025, using ERA5 reanalysis data from the Copernicus programme.

The warmest month is April (27.8 °C on average) and the coldest is January (26.1 °C). Rainfall peaks in October.

Chilaw averages 0 frost days, 67 hot days (≥ 30 °C) and 247 rainy days per year.

Chilaw has warmed by +1.4 °C between 1940 and 2025, or +0.16 °C per decade. This trend is statistically significant.

The hottest day of the period reached 34.7 °C (on 10 March 2010) and the coldest 20.5 °C (on 22 January 1956).

Data from ERA5 reanalysis (Copernicus Climate Change Service), redistributed under a CC-BY 4.0 licence. Normals are recomputed whenever the archive is updated.

Climate normals · ERA5

ChilawNorth Western Province

coords: 7.58°, 79.80°
period: 1940–2025 · 86 yrs

AmTropical monsoonWarmest monthAprilColdest monthJanuaryWettest monthOctoberDriest monthFebruary

Mean daily temperature

26.9°C

Average daily high

28.8°C

Average daily low

25.3°C

Annual rainfall

1,871mm

Sunshine / day

10.4h

Mean relative humidity

82%

Average peak wind

21.3km/h

Seasonal range

1.7°C

Frost days (< 0 °C)

0 d/yr

Hot days (≥ 30 °C)

67 d/yr

Rainy days (≥ 1 mm)

247 d/yr

Annual snowfall

0.0 cm

Average feels-like high

33.4 °C

Average feels-like low

28.5 °C

Average peak gust

36.4 km/h

Tropical nights (≥ 20 °C)

365 d/yr

Solar radiation

19.7 MJ/m²

Has the climate changed?

One stripe per year, 1940 to 2025

+1.4 °C

since 1940

+0.2 °C per decade · r² = 0.78 · p = < 0.001

19402025

Trend fitted by linear regression (ordinary least squares) on annual means. A trend is shown only when it is statistically significant (p < 0.05).

A climograph overlays rainfall (bars) and temperature (line): the standard reading in climatology, where you can see at a glance whether the warm season is also the dry one.

Records for the period

Hottest day

34.7 °C

10 March 2010

Coldest day

20.5 °C

22 January 1956

Wettest day

227 mm

28 November 2025

Windiest day

49.7 km/h

13 November 1992

Strongest gust

87.8 km/h

28 November 2025

Hottest feels-like

41.9 °C

6 April 1998

Coldest feels-like

19.6 °C

13 February 1956

Sunniest day

12.2 h

20 May 1953

Year	Hottest day	Coldest day	Annual mean	Rainfall	Hot days
2025	33.7 °C24 February 2025	23.2 °C4 February 2025	27.5 °C	2,202 mm	118
2024	34.6 °C11 March 2024	23.5 °C25 January 2024	28.0 °C	2,596 mm	165
2023	33.8 °C11 April 2023	21.8 °C13 January 2023	27.6 °C	2,721 mm	138
2022	32.7 °C27 February 2022	22.5 °C21 January 2022	27.4 °C	1,846 mm	110
2021	32.9 °C13 March 2021	22.3 °C11 February 2021	27.4 °C	2,343 mm	112
2020	34.0 °C18 March 2020	22.7 °C15 January 2020	27.8 °C	1,552 mm	167
2019	33.6 °C2 March 2019	22.3 °C19 January 2019	27.6 °C	1,796 mm	162
2018	33.0 °C15 February 2018	21.7 °C7 January 2018	27.2 °C	1,828 mm	112
2017	32.5 °C22 March 2017	21.7 °C8 January 2017	27.4 °C	1,722 mm	95
2016	34.3 °C26 February 2016	21.6 °C24 December 2016	27.8 °C	1,451 mm	148
2015	33.1 °C26 March 2015	22.4 °C18 February 2015	27.5 °C	2,280 mm	137
2014	33.9 °C26 March 2014	21.8 °C6 February 2014	27.3 °C	2,058 mm	114
2013	32.7 °C20 March 2013	22.7 °C19 January 2013	27.2 °C	1,715 mm	96
2012	32.2 °C25 February 2012	22.5 °C18 January 2012	27.3 °C	1,626 mm	81
2011	32.3 °C17 March 2011	21.8 °C14 January 2011	27.1 °C	1,959 mm	56
2010	34.7 °C10 March 2010	22.3 °C23 January 2010	27.4 °C	2,005 mm	114
2009	32.7 °C21 February 2009	22.0 °C14 February 2009	27.3 °C	1,810 mm	80
2008	31.4 °C22 February 2008	22.0 °C19 January 2008	27.1 °C	2,345 mm	37
2007	33.0 °C10 March 2007	21.8 °C4 January 2007	27.3 °C	1,870 mm	114
2006	32.3 °C19 March 2006	20.8 °C25 January 2006	27.1 °C	2,200 mm	69
2005	32.7 °C19 March 2005	22.3 °C28 December 2005	27.3 °C	1,874 mm	100
2004	33.1 °C10 March 2004	21.3 °C22 December 2004	27.2 °C	1,851 mm	109
2003	32.7 °C9 March 2003	22.5 °C2 January 2003	27.3 °C	1,876 mm	83
2002	32.6 °C25 February 2002	22.1 °C15 January 2002	27.2 °C	1,809 mm	90
2001	32.0 °C3 March 2001	20.7 °C11 February 2001	27.0 °C	1,559 mm	40
2000	31.8 °C22 March 2000	22.1 °C21 January 2000	26.8 °C	1,669 mm	27
1999	31.1 °C15 February 1999	20.9 °C31 January 1999	26.7 °C	1,862 mm	34
1998	34.4 °C5 April 1998	23.5 °C16 January 1998	27.6 °C	1,975 mm	120
1997	33.8 °C26 March 1997	21.9 °C28 January 1997	27.2 °C	2,037 mm	94
1996	32.0 °C7 March 1996	22.5 °C25 December 1996	26.9 °C	1,740 mm	83
1995	33.1 °C19 March 1995	22.7 °C24 January 1995	27.1 °C	1,637 mm	90
1994	31.8 °C24 February 1994	22.4 °C12 December 1994	26.8 °C	1,714 mm	52
1993	32.7 °C7 March 1993	20.5 °C9 February 1993	26.8 °C	1,885 mm	62
1992	32.5 °C23 February 1992	22.1 °C14 February 1992	26.9 °C	1,584 mm	96
1991	32.5 °C24 February 1991	22.0 °C13 February 1991	27.1 °C	1,540 mm	76
1990	32.7 °C11 February 1990	20.8 °C20 January 1990	27.1 °C	1,637 mm	73
1989	32.6 °C30 March 1989	21.3 °C12 February 1989	26.8 °C	1,814 mm	74
1988	32.2 °C19 February 1988	21.3 °C8 February 1988	27.2 °C	1,936 mm	80
1987	33.3 °C24 March 1987	22.4 °C11 February 1987	27.4 °C	1,662 mm	104
1986	31.5 °C27 February 1986	22.3 °C4 February 1986	26.8 °C	1,185 mm	49
1985	31.7 °C10 March 1985	22.6 °C21 January 1985	26.8 °C	1,700 mm	59
1984	31.0 °C25 February 1984	21.9 °C14 December 1984	26.5 °C	1,843 mm	24
1983	32.4 °C8 March 1983	21.4 °C4 January 1983	27.3 °C	1,243 mm	111
1982	32.3 °C14 March 1982	21.5 °C16 February 1982	27.0 °C	1,483 mm	91
1981	33.2 °C15 March 1981	21.2 °C8 January 1981	26.9 °C	1,277 mm	69
1980	31.9 °C25 February 1980	22.3 °C25 January 1980	27.1 °C	1,240 mm	88
1979	32.6 °C2 March 1979	22.5 °C11 January 1979	27.2 °C	1,639 mm	95
1978	33.1 °C24 February 1978	22.5 °C19 January 1978	26.8 °C	2,068 mm	79
1977	33.1 °C25 March 1977	21.1 °C29 January 1977	26.7 °C	1,567 mm	65
1976	32.0 °C21 February 1976	21.7 °C21 January 1976	26.6 °C	1,593 mm	39
1975	32.1 °C19 February 1975	20.7 °C10 January 1975	26.4 °C	2,000 mm	30
1974	31.7 °C15 March 1974	21.1 °C16 January 1974	26.5 °C	1,263 mm	43
1973	33.9 °C18 March 1973	22.1 °C17 January 1973	26.9 °C	1,748 mm	105
1972	32.6 °C7 March 1972	21.7 °C13 January 1972	26.7 °C	2,047 mm	48
1971	32.4 °C16 March 1971	21.7 °C13 February 1971	26.4 °C	1,695 mm	27
1970	31.8 °C20 March 1970	21.2 °C2 February 1970	26.7 °C	1,919 mm	31
1969	32.3 °C5 March 1969	21.9 °C27 January 1969	26.8 °C	2,235 mm	68
1968	33.0 °C11 March 1968	21.1 °C28 January 1968	26.6 °C	1,981 mm	40
1967	31.9 °C11 April 1967	21.3 °C10 February 1967	26.5 °C	2,541 mm	35
1966	32.3 °C27 February 1966	22.4 °C2 January 1966	26.6 °C	2,437 mm	35
1965	31.6 °C11 February 1965	22.4 °C25 January 1965	26.4 °C	2,882 mm	24
1964	32.5 °C14 March 1964	22.1 °C19 January 1964	26.6 °C	2,255 mm	58
1963	31.1 °C22 February 1963	21.4 °C11 February 1963	26.4 °C	2,187 mm	19
1962	32.0 °C14 March 1962	22.1 °C16 January 1962	26.5 °C	2,418 mm	18
1961	32.9 °C31 March 1961	22.0 °C19 February 1961	26.4 °C	1,781 mm	37
1960	31.0 °C9 February 1960	21.9 °C4 February 1960	26.4 °C	1,796 mm	19
1959	33.8 °C21 March 1959	23.1 °C4 January 1959	26.8 °C	1,725 mm	66
1958	33.0 °C6 March 1958	22.5 °C5 February 1958	26.8 °C	2,008 mm	34
1957	32.3 °C17 March 1957	22.1 °C25 January 1957	26.5 °C	1,839 mm	30
1956	31.9 °C24 February 1956	20.5 °C22 January 1956	26.0 °C	1,717 mm	23
1955	31.6 °C11 March 1955	21.5 °C30 December 1955	26.1 °C	2,221 mm	15
1954	32.5 °C5 March 1954	22.3 °C29 January 1954	26.2 °C	2,240 mm	30
1953	32.0 °C13 February 1953	22.1 °C30 January 1953	26.7 °C	1,333 mm	79
1952	33.2 °C27 February 1952	22.4 °C15 January 1952	26.8 °C	1,239 mm	89
1951	32.0 °C27 March 1951	21.9 °C5 January 1951	26.6 °C	1,667 mm	25
1950	32.0 °C5 February 1950	21.9 °C2 January 1950	26.4 °C	1,118 mm	33
1949	30.8 °C20 November 1949	22.9 °C23 January 1949	26.4 °C	1,557 mm	30
1948	32.4 °C2 March 1948	23.1 °C5 December 1948	26.5 °C	1,676 mm	25
1947	30.6 °C17 March 1947	22.2 °C29 December 1947	26.4 °C	1,662 mm	4
1946	33.7 °C14 March 1946	20.9 °C16 January 1946	26.3 °C	2,138 mm	35
1945	32.5 °C26 March 1945	20.6 °C5 January 1945	26.4 °C	2,078 mm	22
1944	31.8 °C20 February 1944	22.0 °C6 February 1944	26.3 °C	2,601 mm	33
1943	32.0 °C15 March 1943	21.7 °C19 February 1943	25.9 °C	2,179 mm	28
1942	30.7 °C4 March 1942	21.5 °C4 February 1942	26.0 °C	2,056 mm	15
1941	32.0 °C25 February 1941	21.3 °C27 January 1941	26.3 °C	2,008 mm	43
1940	30.6 °C12 February 1940	21.7 °C11 January 1940	26.2 °C	2,261 mm	9

Normals computed over complete calendar years 1940–2025.

A specific year

Pick a year and see how it compares to normal — warmer, drier or more extreme than usual?

Year

Across the whole year

Average daily high

29.5 °C

+0.7 °C

Hot days (≥ 30 °C)

118 d/yr

+51

Frost days (< 0 °C)

0 d/yr

Annual rainfall

2202 mm

+331 mm

Month by month

	High	vs. normal	Precipitation	vs. normal
Jan	29.1 °C	-0.1 °C	131 mm	+90 mm
Feb	31.5 °C	+1.3 °C	14 mm	-17 mm
Mar	30.8 °C	+0.6 °C	81 mm	+8 mm
Apr	30.2 °C	+0.4 °C	209 mm	+60 mm
May	30.1 °C	+0.9 °C	206 mm	-38 mm
Jun	29.3 °C	+1.0 °C	177 mm	-40 mm
Jul	28.9 °C	+1.0 °C	92 mm	-61 mm
Aug	28.5 °C	+0.7 °C	63 mm	-81 mm
Sep	28.9 °C	+0.9 °C	124 mm	-59 mm
Oct	29.1 °C	+1.0 °C	412 mm	+132 mm
Nov	28.6 °C	+0.1 °C	638 mm	+394 mm
Dec	29.3 °C	+0.7 °C	57 mm	-57 mm

The year's extremes

Hottest day

33.7 °C

24 Feb 2025

Coldest day

23.2 °C

4 Feb 2025

Wettest day

227.2 mm

28 Nov 2025

Windiest day

47.4 km/h

28 Nov 2025

Strongest gust

87.8 km/h

28 Nov 2025

Hottest feels-like

40.4 °C

21 Mar 2025

Coldest feels-like

23.3 °C

28 Nov 2025

Sunniest day

12.1 h

1 Jun 2025

What was the weather like that day?

Your birthday, a wedding, a memorable trip: discover the actual weather for any date since 1940.

Date

Frequently asked questions

What is the climate of Chilaw?

Chilaw has a tropical monsoon climate (Köppen Am). Over 1940-2025, the average annual temperature is 26.9 °C and it receives 1,871 mm of precipitation per year.

What is the hottest day ever recorded in Chilaw?

The hottest day measured in Chilaw between 1940 and 2025 was 10 March 2010, reaching 34.7 °C.

What is the coldest day in Chilaw?

The coldest day measured in Chilaw between 1940 and 2025 was 22 January 1956, at 20.5 °C.

Does it snow in Chilaw?

Almost never: Chilaw sees virtually no snow, with about 0 frost days per year.

Has the climate of Chilaw warmed?

Yes: Chilaw warmed by +1.4 °C between 1940 and 2025, a statistically significant trend.

What is the wettest day in Chilaw?

The wettest day measured in Chilaw between 1940 and 2025 was 28 November 2025, with 227 mm of rain in 24 hours.

What was the windiest day in Chilaw?

The windiest day measured in Chilaw between 1940 and 2025 was 13 November 1992, with winds reaching 49.7 km/h.

What is the warmest month in Chilaw?

The warmest month in Chilaw is April (27.8 °C on average); the coldest is January (26.1 °C).

How much does it rain in Chilaw?

Chilaw receives on average 1,871 mm of precipitation per year, spread over about 247 rainy days.

Is it sunny in Chilaw?

Chilaw gets on average 10.4 hours of sunshine per day, roughly 3,796 hours per year over 1940-2025.

Are there tropical nights in Chilaw?

Yes: Chilaw has on average 365 tropical nights per year (temperature staying above 20 °C), over 1940-2025.

What was the most extreme apparent temperature in Chilaw?

In Chilaw, between 1940 and 2025, the highest apparent temperature reached 41.9 °C on 6 April 1998, and the lowest was 19.6 °C on 13 February 1956.

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