Siaya climate — normals and trends

Q: What is the climate of Siaya?

Siaya has a tropical rainforest climate (Köppen Af). Over 1940-2025, the average annual temperature is 22.0 °C and it receives 2,339 mm of precipitation per year.

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

The hottest day measured in Siaya between 1940 and 2025 was 23 February 2005, reaching 33.9 °C.

Q: What is the coldest day in Siaya?

The coldest day measured in Siaya between 1940 and 2025 was 27 July 1943, at 15.2 °C.

Q: Does it snow in Siaya?

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

Q: Has the climate of Siaya warmed?

Yes: Siaya warmed by +2.0 °C between 1940 and 2025, a statistically significant trend.

Q: What is the wettest day in Siaya?

The wettest day measured in Siaya between 1940 and 2025 was 9 March 1978, with 195 mm of rain in 24 hours.

Q: What was the windiest day in Siaya?

The windiest day measured in Siaya between 1940 and 2025 was 22 February 1946, with winds reaching 27.9 km/h.

Q: What is the warmest month in Siaya?

The warmest month in Siaya is February (22.7 °C on average); the coldest is July (21.4 °C).

Q: How much does it rain in Siaya?

Siaya receives on average 2,339 mm of precipitation per year, spread over about 296 rainy days.

Q: Is it sunny in Siaya?

Siaya gets on average 10.9 hours of sunshine per day, roughly 3,979 hours per year over 1940-2025.

Siaya (Kenya) has a tropical rainforest climate (Af) under the Köppen-Geiger classification. Its mean annual temperature is 22.0 °C and it receives 2,339 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 February (22.7 °C on average) and the coldest is July (21.4 °C). Rainfall peaks in April.

Siaya averages 0 frost days, 8 hot days (≥ 30 °C) and 296 rainy days per year.

Siaya has warmed by +2.0 °C between 1940 and 2025, or +0.23 °C per decade. This trend is statistically significant.

The hottest day of the period reached 33.9 °C (on 23 February 2005) and the coldest 15.2 °C (on 27 July 1943).

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

SiayaSiaya County

coords: 0.06°, 34.29°
period: 1940–2025 · 86 yrs

AfTropical rainforestWarmest monthFebruaryColdest monthJulyWettest monthAprilDriest monthJuly

Mean daily temperature

22.0°C

Average daily high

26.0°C

Average daily low

18.9°C

Annual rainfall

2,339mm

Sunshine / day

10.9h

Mean relative humidity

79%

Average peak wind

11.8km/h

Seasonal range

1.3°C

Frost days (< 0 °C)

0 d/yr

Hot days (≥ 30 °C)

8 d/yr

Rainy days (≥ 1 mm)

296 d/yr

Annual snowfall

0.0 cm

Average feels-like high

29.6 °C

Average feels-like low

20.5 °C

Average peak gust

25.8 km/h

Tropical nights (≥ 20 °C)

52 d/yr

Solar radiation

21.5 MJ/m²

Has the climate changed?

One stripe per year, 1940 to 2025

+2.0 °C

since 1940

+0.2 °C per decade · r² = 0.76 · 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

33.9 °C

23 February 2005

Coldest day

15.2 °C

27 July 1943

Wettest day

195 mm

9 March 1978

Windiest day

27.9 km/h

22 February 1946

Strongest gust

52.6 km/h

22 February 1946

Hottest feels-like

37.3 °C

25 February 2005

Coldest feels-like

14.3 °C

27 July 1943

Sunniest day

12.0 h

10 February 1941

Year	Hottest day	Coldest day	Annual mean	Rainfall	Hot days
2025	33.4 °C25 February 2025	17.7 °C17 August 2025	23.1 °C	1,898 mm	28
2024	31.7 °C15 March 2024	18.2 °C28 November 2024	23.3 °C	2,147 mm	9
2023	33.4 °C19 February 2023	17.8 °C6 January 2023	23.2 °C	2,330 mm	19
2022	31.8 °C13 January 2022	16.7 °C3 August 2022	22.8 °C	2,019 mm	10
2021	31.4 °C13 March 2021	17.7 °C24 June 2021	22.7 °C	1,749 mm	4
2020	29.5 °C23 February 2020	17.3 °C19 July 2020	22.6 °C	2,482 mm	0
2019	32.8 °C24 March 2019	17.7 °C3 August 2019	22.9 °C	2,411 mm	27
2018	32.6 °C11 February 2018	17.1 °C1 July 2018	22.7 °C	2,180 mm	18
2017	32.6 °C17 January 2017	18.1 °C4 September 2017	23.2 °C	1,739 mm	33
2016	32.2 °C28 February 2016	17.9 °C28 August 2016	23.4 °C	1,531 mm	31
2015	33.8 °C9 March 2015	18.1 °C4 July 2015	23.0 °C	2,036 mm	33
2014	32.5 °C2 March 2014	17.3 °C13 February 2014	22.8 °C	1,815 mm	13
2013	32.8 °C27 February 2013	16.7 °C16 July 2013	22.6 °C	1,827 mm	15
2012	33.2 °C5 February 2012	17.0 °C3 January 2012	22.5 °C	2,024 mm	29
2011	32.2 °C27 February 2011	16.9 °C27 January 2011	22.5 °C	2,202 mm	16
2010	31.8 °C2 February 2010	17.1 °C29 December 2010	22.7 °C	2,031 mm	10
2009	31.5 °C13 January 2009	17.1 °C1 July 2009	22.8 °C	1,960 mm	15
2008	30.8 °C25 February 2008	17.3 °C16 July 2008	22.5 °C	1,905 mm	11
2007	32.1 °C20 February 2007	17.5 °C18 December 2007	22.5 °C	1,968 mm	8
2006	33.0 °C26 January 2006	17.2 °C17 December 2006	22.6 °C	2,497 mm	23
2005	33.9 °C23 February 2005	16.7 °C11 July 2005	23.0 °C	1,737 mm	33
2004	31.7 °C13 February 2004	17.0 °C4 July 2004	22.6 °C	2,085 mm	10
2003	33.1 °C21 February 2003	17.4 °C1 July 2003	22.7 °C	1,704 mm	24
2002	31.2 °C23 February 2002	17.7 °C9 June 2002	22.6 °C	2,062 mm	8
2001	31.2 °C28 February 2001	16.3 °C22 July 2001	22.2 °C	1,915 mm	6
2000	31.2 °C21 February 2000	16.9 °C19 August 2000	22.4 °C	1,811 mm	11
1999	32.9 °C17 February 1999	16.9 °C26 July 1999	22.2 °C	1,950 mm	21
1998	30.8 °C13 March 1998	17.5 °C1 July 1998	22.8 °C	2,024 mm	5
1997	32.0 °C7 March 1997	16.7 °C14 July 1997	22.7 °C	2,651 mm	23
1996	29.6 °C29 December 1996	17.1 °C10 August 1996	22.2 °C	2,035 mm	0
1995	29.8 °C5 February 1995	17.3 °C21 December 1995	22.4 °C	2,240 mm	0
1994	30.6 °C21 January 1994	17.0 °C4 July 1994	22.2 °C	2,466 mm	3
1993	31.2 °C30 December 1993	16.9 °C11 March 1993	22.3 °C	1,926 mm	1
1992	31.7 °C12 March 1992	16.9 °C21 December 1992	22.1 °C	2,153 mm	7
1991	30.9 °C17 March 1991	16.9 °C24 July 1991	22.0 °C	2,450 mm	3
1990	29.6 °C28 January 1990	16.7 °C1 October 1990	22.1 °C	2,390 mm	0
1989	31.2 °C1 March 1989	15.8 °C21 June 1989	21.8 °C	2,495 mm	4
1988	31.2 °C1 March 1988	16.7 °C30 June 1988	22.1 °C	2,432 mm	3
1987	30.7 °C29 December 1987	17.1 °C24 June 1987	22.4 °C	2,414 mm	4
1986	28.7 °C24 February 1986	16.2 °C29 July 1986	21.7 °C	2,690 mm	0
1985	32.2 °C16 March 1985	15.8 °C17 July 1985	21.6 °C	2,563 mm	5
1984	31.4 °C21 February 1984	15.7 °C23 December 1984	21.7 °C	2,280 mm	5
1983	30.5 °C26 February 1983	16.7 °C2 December 1983	22.1 °C	2,245 mm	5
1982	31.0 °C26 March 1982	16.8 °C28 June 1982	21.8 °C	2,479 mm	3
1981	31.5 °C2 March 1981	16.4 °C8 December 1981	21.9 °C	2,218 mm	6
1980	32.1 °C22 February 1980	16.2 °C24 July 1980	22.0 °C	2,125 mm	10
1979	30.0 °C28 February 1979	16.1 °C18 July 1979	21.8 °C	2,710 mm	2
1978	31.4 °C7 February 1978	15.9 °C18 July 1978	21.6 °C	2,988 mm	2
1977	29.2 °C29 September 1977	15.6 °C14 August 1977	21.6 °C	2,679 mm	0
1976	30.4 °C30 January 1976	15.5 °C4 January 1976	21.4 °C	2,642 mm	2
1975	30.3 °C26 January 1975	15.8 °C27 July 1975	21.3 °C	2,825 mm	1
1974	31.0 °C16 March 1974	15.3 °C28 July 1974	21.3 °C	2,583 mm	4
1973	30.7 °C6 February 1973	16.5 °C2 July 1973	21.8 °C	2,450 mm	2
1972	28.8 °C31 August 1972	16.3 °C2 January 1972	21.3 °C	3,319 mm	0
1971	30.7 °C6 March 1971	16.3 °C9 February 1971	21.1 °C	2,684 mm	3
1970	29.6 °C8 February 1970	16.2 °C25 July 1970	21.4 °C	2,574 mm	0
1969	29.5 °C2 October 1969	16.1 °C3 August 1969	21.7 °C	2,146 mm	0
1968	29.2 °C6 October 1968	15.7 °C26 July 1968	21.2 °C	3,085 mm	0
1967	29.9 °C12 February 1967	16.2 °C29 July 1967	21.4 °C	2,852 mm	0
1966	28.8 °C4 August 1966	16.2 °C20 June 1966	21.6 °C	2,696 mm	0
1965	29.8 °C27 February 1965	15.8 °C5 January 1965	21.6 °C	2,525 mm	0
1964	28.2 °C31 January 1964	15.6 °C11 August 1964	21.2 °C	2,827 mm	0
1963	29.8 °C8 September 1963	15.8 °C17 June 1963	21.1 °C	3,221 mm	0
1962	28.8 °C14 February 1962	16.1 °C2 July 1962	20.9 °C	2,968 mm	0
1961	31.6 °C21 January 1961	15.9 °C14 February 1961	21.5 °C	3,614 mm	11
1960	29.4 °C12 December 1960	16.3 °C10 September 1960	21.7 °C	3,058 mm	0
1959	30.6 °C15 March 1959	16.0 °C21 July 1959	21.9 °C	2,941 mm	5
1958	31.0 °C3 March 1958	15.8 °C5 August 1958	21.8 °C	2,610 mm	5
1957	29.9 °C22 September 1957	16.3 °C20 July 1957	21.7 °C	2,994 mm	0
1956	28.6 °C3 March 1956	16.0 °C23 July 1956	20.9 °C	2,428 mm	0
1955	27.7 °C18 March 1955	16.5 °C20 August 1955	21.0 °C	2,418 mm	0
1954	27.4 °C24 November 1954	16.5 °C6 January 1954	21.1 °C	2,079 mm	0
1953	27.8 °C2 October 1953	15.9 °C12 August 1953	20.8 °C	3,765 mm	0
1952	28.7 °C23 January 1952	17.0 °C9 July 1952	21.2 °C	2,770 mm	0
1951	27.7 °C7 October 1951	15.8 °C17 July 1951	21.0 °C	3,200 mm	0
1950	28.5 °C2 March 1950	15.7 °C18 July 1950	20.8 °C	2,354 mm	0
1949	28.2 °C31 October 1949	16.1 °C1 August 1949	21.3 °C	2,223 mm	0
1948	27.4 °C23 March 1948	16.5 °C29 July 1948	21.2 °C	2,531 mm	0
1947	28.6 °C10 October 1947	15.8 °C26 July 1947	21.3 °C	2,443 mm	0
1946	32.9 °C24 February 1946	16.3 °C5 August 1946	21.7 °C	1,705 mm	35
1945	29.5 °C26 December 1945	16.9 °C30 July 1945	21.5 °C	1,614 mm	0
1944	32.1 °C2 March 1944	15.9 °C6 July 1944	22.1 °C	1,584 mm	19
1943	31.5 °C19 February 1943	15.2 °C27 July 1943	21.9 °C	1,128 mm	22
1942	31.1 °C8 February 1942	16.4 °C15 July 1942	21.7 °C	1,368 mm	10
1941	30.9 °C26 March 1941	16.4 °C20 December 1941	21.6 °C	1,896 mm	3
1940	28.0 °C26 December 1940	16.4 °C11 January 1940	20.8 °C	2,381 mm	0

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

27.1 °C

+1.1 °C

Hot days (≥ 30 °C)

28 d/yr

+20

Frost days (< 0 °C)

0 d/yr

Annual rainfall

1898 mm

-441 mm

Month by month

	High	vs. normal	Precipitation	vs. normal
Jan	27.3 °C	+0.8 °C	86 mm	-66 mm
Feb	30.2 °C	+3.1 °C	23 mm	-128 mm
Mar	28.1 °C	+1.4 °C	285 mm	+38 mm
Apr	26.5 °C	+0.8 °C	310 mm	+3 mm
May	26.5 °C	+1.0 °C	197 mm	-69 mm
Jun	26.4 °C	+1.0 °C	105 mm	-35 mm
Jul	26.0 °C	+0.8 °C	135 mm	+31 mm
Aug	26.0 °C	+0.2 °C	142 mm	+17 mm
Sep	27.6 °C	+1.3 °C	107 mm	-51 mm
Oct	26.8 °C	+0.8 °C	213 mm	-5 mm
Nov	27.3 °C	+1.9 °C	85 mm	-176 mm
Dec	27.0 °C	+1.2 °C	210 mm	+0 mm

The year's extremes

Hottest day

33.4 °C

25 Feb 2025

Coldest day

17.7 °C

17 Aug 2025

Wettest day

101.2 mm

20 Mar 2025

Windiest day

24.2 km/h

3 Mar 2025

Strongest gust

44.3 km/h

3 Mar 2025

Hottest feels-like

36.9 °C

5 Mar 2025

Coldest feels-like

18.1 °C

17 Aug 2025

Sunniest day

11.9 h

5 Mar 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 Siaya?

Siaya has a tropical rainforest climate (Köppen Af). Over 1940-2025, the average annual temperature is 22.0 °C and it receives 2,339 mm of precipitation per year.

What is the hottest day ever recorded in Siaya?

The hottest day measured in Siaya between 1940 and 2025 was 23 February 2005, reaching 33.9 °C.

What is the coldest day in Siaya?

The coldest day measured in Siaya between 1940 and 2025 was 27 July 1943, at 15.2 °C.

Does it snow in Siaya?

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

Has the climate of Siaya warmed?

Yes: Siaya warmed by +2.0 °C between 1940 and 2025, a statistically significant trend.

What is the wettest day in Siaya?

The wettest day measured in Siaya between 1940 and 2025 was 9 March 1978, with 195 mm of rain in 24 hours.

What was the windiest day in Siaya?

The windiest day measured in Siaya between 1940 and 2025 was 22 February 1946, with winds reaching 27.9 km/h.

What is the warmest month in Siaya?

The warmest month in Siaya is February (22.7 °C on average); the coldest is July (21.4 °C).

How much does it rain in Siaya?

Siaya receives on average 2,339 mm of precipitation per year, spread over about 296 rainy days.

Is it sunny in Siaya?

Siaya gets on average 10.9 hours of sunshine per day, roughly 3,979 hours per year over 1940-2025.

Are there tropical nights in Siaya?

Yes: Siaya has on average 52 tropical nights per year (temperature staying above 20 °C), over 1940-2025.

What was the most extreme apparent temperature in Siaya?

In Siaya, between 1940 and 2025, the highest apparent temperature reached 37.3 °C on 25 February 2005, and the lowest was 14.3 °C on 27 July 1943.

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