Koster climate — normals and trends

Q: What is the climate of Koster?

Koster has a humid subtropical, dry winter climate (Köppen Cwa). Over 1940-2025, the average annual temperature is 18.0 °C and it receives 655 mm of precipitation per year.

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

The hottest day measured in Koster between 1940 and 2025 was 7 January 2016, reaching 40.0 °C.

Q: What is the coldest day in Koster?

The coldest day measured in Koster between 1940 and 2025 was 9 July 2024, at -1.8 °C.

Q: Does it snow in Koster?

Almost never: Koster sees virtually no snow, with about 1 frost days per year.

Q: Has the climate of Koster warmed?

Yes: Koster warmed by +1.1 °C between 1940 and 2025, a statistically significant trend.

Q: What is the wettest day in Koster?

The wettest day measured in Koster between 1940 and 2025 was 31 December 1993, with 196 mm of rain in 24 hours.

Q: What was the windiest day in Koster?

The windiest day measured in Koster between 1940 and 2025 was 25 August 1970, with winds reaching 38.8 km/h.

Q: What is the warmest month in Koster?

The warmest month in Koster is January (22.4 °C on average); the coldest is June (11.3 °C).

Q: How much does it rain in Koster?

Koster receives on average 655 mm of precipitation per year, spread over about 96 rainy days.

Q: Is it sunny in Koster?

Koster gets on average 10.8 hours of sunshine per day, roughly 3,942 hours per year over 1940-2025.

Koster (South Africa) has a humid subtropical, dry winter climate (Cwa) under the Köppen-Geiger classification. Its mean annual temperature is 18.0 °C and it receives 655 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 January (22.4 °C on average) and the coldest is June (11.3 °C). Rainfall peaks in December.

Koster averages 1 frost days, 48 hot days (≥ 30 °C) and 96 rainy days per year.

Koster has warmed by +1.1 °C between 1940 and 2025, or +0.13 °C per decade. This trend is statistically significant.

The hottest day of the period reached 40.0 °C (on 7 January 2016) and the coldest -1.8 °C (on 9 July 2024).

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

KosterNorth West

coords: -25.86°, 26.90°
period: 1940–2025 · 86 yrs

CwaHumid subtropical, dry winterWarmest monthJanuaryColdest monthJuneWettest monthDecemberDriest monthJuly

Mean daily temperature

18.0°C

Average daily high

24.6°C

Average daily low

12.6°C

Annual rainfall

655mm

Sunshine / day

10.8h

Mean relative humidity

57%

Average peak wind

15.3km/h

Seasonal range

11.1°C

Frost days (< 0 °C)

1 d/yr

Hot days (≥ 30 °C)

48 d/yr

Rainy days (≥ 1 mm)

96 d/yr

Annual snowfall

0.0 cm

Average feels-like high

24.0 °C

Average feels-like low

11.0 °C

Average peak gust

33.7 km/h

Tropical nights (≥ 20 °C)

8 d/yr

Solar radiation

20.2 MJ/m²

Has the climate changed?

One stripe per year, 1940 to 2025

+1.1 °C

since 1940

+0.1 °C per decade · r² = 0.19 · 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

40.0 °C

7 January 2016

Coldest day

-1.8 °C

9 July 2024

Wettest day

196 mm

31 December 1993

Windiest day

38.8 km/h

25 August 1970

Strongest gust

83.9 km/h

9 September 2002

Hottest feels-like

40.4 °C

7 January 2016

Coldest feels-like

-6.8 °C

12 July 1985

Snowiest day

0.4 cm

18 July 1965

Sunniest day

13.6 h

13 December 2024

Year	Hottest day	Coldest day	Annual mean	Rainfall	Hot days	Frost days
2025	33.8 °C15 October 2025	0.8 °C5 July 2025	18.0 °C	985 mm	31	0
2024	36.9 °C7 December 2024	-1.8 °C9 July 2024	19.7 °C	408 mm	105	3
2023	35.1 °C5 December 2023	0.4 °C10 July 2023	18.8 °C	485 mm	81	0
2022	35.4 °C4 October 2022	1.1 °C17 June 2022	18.3 °C	738 mm	37	0
2021	35.2 °C16 November 2021	0.1 °C14 July 2021	18.1 °C	705 mm	46	0
2020	35.6 °C19 October 2020	-0.4 °C17 July 2020	18.5 °C	534 mm	55	1
2019	36.4 °C21 October 2019	2.7 °C25 June 2019	19.8 °C	534 mm	113	0
2018	37.7 °C26 December 2018	1.5 °C3 July 2018	19.5 °C	449 mm	100	0
2017	36.1 °C7 November 2017	1.8 °C9 June 2017	18.7 °C	622 mm	60	0
2016	40.0 °C7 January 2016	0.5 °C28 July 2016	19.8 °C	577 mm	105	0
2015	38.2 °C7 December 2015	1.9 °C18 July 2015	20.2 °C	309 mm	126	0
2014	35.4 °C5 December 2014	-0.5 °C9 July 2014	18.5 °C	591 mm	62	1
2013	36.9 °C25 January 2013	1.4 °C13 August 2013	19.1 °C	415 mm	107	0
2012	35.8 °C6 November 2012	1.7 °C10 June 2012	18.7 °C	584 mm	66	0
2011	37.6 °C24 October 2011	0.5 °C2 July 2011	17.8 °C	699 mm	36	0
2010	35.8 °C13 November 2010	-0.1 °C17 June 2010	18.4 °C	773 mm	51	1
2009	33.9 °C8 October 2009	0.7 °C24 July 2009	18.1 °C	651 mm	45	0
2008	34.3 °C14 October 2008	1.3 °C7 July 2008	17.9 °C	594 mm	38	0
2007	35.1 °C22 February 2007	0.2 °C24 May 2007	18.3 °C	410 mm	70	0
2006	34.9 °C25 October 2006	1.1 °C28 June 2006	17.3 °C	747 mm	22	0
2005	36.1 °C3 November 2005	3.2 °C8 July 2005	18.8 °C	548 mm	67	0
2004	34.5 °C10 November 2004	0.5 °C17 July 2004	17.7 °C	653 mm	45	0
2003	35.2 °C15 December 2003	-1.0 °C21 August 2003	18.7 °C	436 mm	74	1
2002	34.3 °C19 October 2002	1.4 °C18 July 2002	18.1 °C	464 mm	56	0
2001	36.2 °C11 January 2001	-0.4 °C20 July 2001	17.6 °C	726 mm	42	1
2000	32.7 °C17 October 2000	-1.0 °C17 July 2000	17.1 °C	1,100 mm	24	2
1999	35.0 °C4 November 1999	1.8 °C30 June 1999	18.3 °C	515 mm	44	0
1998	35.2 °C8 February 1998	-0.7 °C5 July 1998	18.4 °C	620 mm	64	1
1997	34.3 °C23 February 1997	0.5 °C30 June 1997	17.4 °C	772 mm	42	0
1996	32.3 °C3 November 1996	-0.1 °C20 July 1996	17.2 °C	847 mm	17	1
1995	33.9 °C11 October 1995	0.2 °C19 July 1995	17.9 °C	753 mm	46	0
1994	34.2 °C23 December 1994	-0.7 °C3 July 1994	17.2 °C	464 mm	34	3
1993	34.0 °C9 January 1993	1.1 °C18 June 1993	18.3 °C	690 mm	33	0
1992	36.2 °C27 February 1992	0.2 °C26 June 1992	18.7 °C	402 mm	83	0
1991	32.6 °C8 October 1991	0.1 °C28 July 1991	17.8 °C	629 mm	33	0
1990	33.8 °C19 November 1990	-0.2 °C1 July 1990	17.9 °C	576 mm	49	1
1989	34.2 °C19 October 1989	-0.4 °C23 July 1989	17.4 °C	668 mm	29	1
1988	34.7 °C30 January 1988	0.1 °C10 June 1988	17.6 °C	727 mm	28	0
1987	34.9 °C4 November 1987	0.8 °C21 June 1987	18.2 °C	718 mm	55	0
1986	32.5 °C22 February 1986	3.2 °C25 July 1986	18.0 °C	714 mm	21	0
1985	34.4 °C4 January 1985	-0.8 °C13 July 1985	18.0 °C	702 mm	34	1
1984	35.3 °C15 February 1984	1.1 °C4 July 1984	18.4 °C	463 mm	64	0
1983	34.8 °C11 January 1983	1.0 °C26 June 1983	18.5 °C	509 mm	54	0
1982	35.2 °C28 December 1982	-0.7 °C17 June 1982	17.8 °C	624 mm	44	1
1981	36.3 °C6 November 1981	0.8 °C10 June 1981	16.9 °C	691 mm	32	0
1980	33.8 °C2 January 1980	0.8 °C30 June 1980	17.2 °C	550 mm	19	0
1979	34.1 °C7 January 1979	-0.4 °C25 July 1979	17.6 °C	687 mm	32	2
1978	32.9 °C25 November 1978	-1.4 °C14 June 1978	17.3 °C	639 mm	17	2
1977	32.6 °C22 January 1977	1.3 °C27 June 1977	17.4 °C	703 mm	30	0
1976	31.1 °C17 September 1976	-0.8 °C21 June 1976	16.5 °C	744 mm	6	3
1975	32.9 °C1 January 1975	0.6 °C24 July 1975	16.9 °C	763 mm	21	0
1974	32.1 °C14 October 1974	1.8 °C3 June 1974	16.7 °C	721 mm	7	0
1973	35.7 °C19 January 1973	2.0 °C10 July 1973	17.5 °C	913 mm	37	0
1972	35.3 °C3 December 1972	-0.8 °C2 August 1972	17.6 °C	670 mm	43	1
1971	32.8 °C26 December 1971	1.9 °C17 July 1971	17.4 °C	646 mm	20	0
1970	34.6 °C27 November 1970	0.0 °C23 July 1970	18.4 °C	657 mm	67	0
1969	36.0 °C18 November 1969	0.9 °C20 July 1969	17.9 °C	620 mm	47	0
1968	34.0 °C7 November 1968	-1.1 °C15 June 1968	17.2 °C	537 mm	46	4
1967	33.3 °C16 December 1967	-1.3 °C12 June 1967	16.9 °C	820 mm	25	1
1966	35.1 °C2 January 1966	2.5 °C21 July 1966	17.8 °C	654 mm	48	0
1965	35.1 °C29 October 1965	-0.4 °C19 July 1965	18.0 °C	363 mm	67	1
1964	36.4 °C23 February 1964	-1.2 °C27 June 1964	17.9 °C	515 mm	62	4
1963	35.1 °C29 December 1963	-0.2 °C25 July 1963	17.7 °C	569 mm	43	2
1962	34.9 °C17 October 1962	0.3 °C14 June 1962	18.3 °C	872 mm	61	0
1961	35.4 °C22 October 1961	2.9 °C7 August 1961	17.8 °C	851 mm	39	0
1960	34.3 °C13 January 1960	0.6 °C22 July 1960	17.4 °C	901 mm	45	0
1959	35.1 °C17 October 1959	3.7 °C18 July 1959	17.7 °C	675 mm	44	0
1958	32.7 °C23 November 1958	1.7 °C17 June 1958	17.5 °C	1,036 mm	29	0
1957	34.4 °C21 November 1957	-1.2 °C20 June 1957	17.4 °C	753 mm	24	1
1956	35.3 °C2 February 1956	0.5 °C11 June 1956	17.7 °C	830 mm	15	0
1955	32.9 °C12 November 1955	-1.6 °C29 June 1955	16.6 °C	699 mm	22	1
1954	35.6 °C25 October 1954	-0.6 °C28 July 1954	18.9 °C	292 mm	116	2
1953	36.5 °C31 October 1953	0.1 °C30 July 1953	18.2 °C	648 mm	50	0
1952	36.3 °C20 November 1952	1.0 °C27 July 1952	18.3 °C	731 mm	53	0
1951	35.6 °C9 October 1951	2.1 °C13 July 1951	17.8 °C	706 mm	54	0
1950	34.2 °C30 December 1950	2.7 °C10 August 1950	17.6 °C	734 mm	43	0
1949	37.9 °C9 January 1949	3.0 °C25 August 1949	18.3 °C	543 mm	63	0
1948	34.5 °C1 December 1948	1.2 °C23 July 1948	17.1 °C	803 mm	40	0
1947	36.7 °C8 October 1947	0.6 °C13 July 1947	17.3 °C	796 mm	37	0
1946	35.6 °C29 October 1946	1.6 °C14 August 1946	17.4 °C	757 mm	35	0
1945	34.7 °C7 November 1945	1.0 °C9 July 1945	17.8 °C	738 mm	35	0
1944	34.5 °C26 September 1944	2.1 °C9 July 1944	17.5 °C	728 mm	25	0
1943	33.1 °C10 October 1943	0.9 °C21 July 1943	17.3 °C	897 mm	13	0
1942	33.1 °C9 January 1942	1.1 °C22 July 1942	17.2 °C	879 mm	17	0
1941	36.3 °C16 October 1941	1.1 °C30 June 1941	19.4 °C	384 mm	79	0
1940	35.9 °C30 November 1940	1.4 °C16 July 1940	18.9 °C	466 mm	84	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

24.3 °C

-0.3 °C

Hot days (≥ 30 °C)

31 d/yr

-17

Frost days (< 0 °C)

0 d/yr

-1

Annual rainfall

985 mm

+330 mm

Month by month

	High	vs. normal	Precipitation	vs. normal
Jan	27.6 °C	-0.3 °C	193 mm	+84 mm
Feb	26.7 °C	-0.6 °C	242 mm	+137 mm
Mar	25.6 °C	-0.5 °C	81 mm	+4 mm
Apr	22.3 °C	-1.4 °C	111 mm	+62 mm
May	21.2 °C	-0.3 °C	9 mm	-8 mm
Jun	19.5 °C	+0.6 °C	2 mm	-4 mm
Jul	19.3 °C	+0.3 °C	5 mm	+2 mm
Aug	23.9 °C	+2.0 °C	0 mm	-7 mm
Sep	27.3 °C	+1.5 °C	14 mm	-3 mm
Oct	27.5 °C	0.0 °C	39 mm	-14 mm
Nov	25.1 °C	-2.4 °C	105 mm	+16 mm
Dec	26.3 °C	-1.3 °C	185 mm	+62 mm

The year's extremes

Hottest day

33.8 °C

15 Oct 2025

Coldest day

0.8 °C

5 Jul 2025

Wettest day

55.0 mm

18 Feb 2025

Windiest day

28.2 km/h

21 May 2025

Strongest gust

56.5 km/h

16 Nov 2025

Hottest feels-like

36.2 °C

9 Feb 2025

Coldest feels-like

-3.3 °C

28 Jun 2025

Sunniest day

13.6 h

11 Dec 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 Koster?

Koster has a humid subtropical, dry winter climate (Köppen Cwa). Over 1940-2025, the average annual temperature is 18.0 °C and it receives 655 mm of precipitation per year.

What is the hottest day ever recorded in Koster?

The hottest day measured in Koster between 1940 and 2025 was 7 January 2016, reaching 40.0 °C.

What is the coldest day in Koster?

The coldest day measured in Koster between 1940 and 2025 was 9 July 2024, at -1.8 °C.

Does it snow in Koster?

Almost never: Koster sees virtually no snow, with about 1 frost days per year.

Has the climate of Koster warmed?

Yes: Koster warmed by +1.1 °C between 1940 and 2025, a statistically significant trend.

What is the wettest day in Koster?

The wettest day measured in Koster between 1940 and 2025 was 31 December 1993, with 196 mm of rain in 24 hours.

What was the windiest day in Koster?

The windiest day measured in Koster between 1940 and 2025 was 25 August 1970, with winds reaching 38.8 km/h.

What is the warmest month in Koster?

The warmest month in Koster is January (22.4 °C on average); the coldest is June (11.3 °C).

How much does it rain in Koster?

Koster receives on average 655 mm of precipitation per year, spread over about 96 rainy days.

Is it sunny in Koster?

Koster gets on average 10.8 hours of sunshine per day, roughly 3,942 hours per year over 1940-2025.

What is the biggest single-day snowfall in Koster?

The heaviest 24-hour snowfall measured in Koster between 1940 and 2025 was 18 July 1965, with 0.4 cm.

Are there tropical nights in Koster?

Yes: Koster has on average 8 tropical nights per year (temperature staying above 20 °C), over 1940-2025.

What was the most extreme apparent temperature in Koster?

In Koster, between 1940 and 2025, the highest apparent temperature reached 40.4 °C on 7 January 2016, and the lowest was -6.8 °C on 12 July 1985.

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