Koster weather in April

In April, Koster sees average daytime highs of 24°C and overnight lows near 13°C, with 36 mm of rain across 6.5 wet days and about 11.4 hours of daylight. It is the 8th-warmest and 7th-wettest month of the year here.

Highs ease over the month, from about 25°C in the first days to 24°C by the end. The sky is clear or mostly clear about 59% of the time in April, and the air most often feels dry.

Daylight stretches from about 11 h 48 min at the start of April to 11 h 06 min by month's end. Set against the rest of the year, April is Koster's 7th-clearest and 11th-windiest month. For the whole year in context, see Koster's year-round climate.

Daytime high
24°
8th warmest
Overnight low
13°
6th coldest
Rainfall
36 mm
6.5 wet days
Daylight
11 h 24 min
6:31 AM – 5:54 PM
Cloud cover
38%
7th clearest
Wind
8 km/h
11th windiest
Solar energy
4.8 kWh/m²
Travel score
7.8
out of 10

Koster is place in North West, South Africa.

Founded
1860

Air quality: WHO Ambient Air Quality Database. Density & description: Wikidata (CC0), GeoNames.

Temperature in April

Average highAverage lowShaded bands: 10–90% of days

Highs ease over the month, from about 25°C in the first days to 24°C by the end.

A typical April day in Koster reaches about 24°C in the afternoon and slips back to 13°C overnight — a 11°C spread between the day's warmth and the night's chill. On most days the high lands between 20°C and 28°C. Set against its neighbours, April runs about 2°C cooler than March and about 2°C warmer than May.

10°15°20°25°30°151015202530
Avg high (°C)Avg low (°C)
12515
22515
32515
42514
52514
62514
72514
82514
92514
102514
112513
122413
132413
142413
152413
162413
172413
182413
192413
202412
212412
222412
232412
242412
252412
262412
272411
282411
292411
302411

Koster weather by month

How April compares with the rest of the year at a glance. April is the 8th-warmest and 7th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan28° / 18°9814.413.45.5
Feb28° / 18°9612.312.95.9
Mar27° / 16°7611.112.26.7
Apr24° / 13°366.511.47.8
May22° / 182.210.88.7
Jun20° / 81.210.48.4
Jul20° / 30.510.58.5
Aug23° / 81.411.19.0
Sep26° / 12°142.211.88.5
Oct28° / 15°527.812.67.0
Nov28° / 16°7812.113.35.9
Dec28° / 17°12114.813.65.5

Cloud cover in April

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 59% of the time in April.

Beyond those clear spells, partly cloudy skies cover about 17% of April, with mostly cloudy or overcast conditions the remaining 23%. Skies tend to open up as the month goes on.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
17129
27129
37129
47129
57129
67327
77327
87327
97426
107426
117426
127525
137624
147624
157723
167723
177822
187822
197822
208020
218020
228020
237921
248020
258020
268020
278218
288218
298317
308317

Chance of precipitation in April

Any precipitation

Koster gets around 36 mm of rain over 6.5 wet days in April. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 22% and peaks near 30% on the wettest days. The odds ease toward the end of the month.

0%10%20%30%40%151015202530
Rain chance (%)
130
229
328
428
527
626
726
825
924
1024
1124
1223
1323
1423
1522
1622
1722
1821
1921
2020
2120
2219
2319
2419
2518
2618
2717
2816
2916
3015

Humidity in April

DryComfortableHumidMuggyOppressiveMiserable

Most of April feels dry — the stacked bands show each day's mix of comfort levels, read off the dew point.

By dew point, April lands in the dry band about 76% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)Humid (%)
1503812
2523711
3543610
456359
558348
660337
763316
865305
967294
1070273
1171263
1273252
1374242
1477221
1578211
1679201
1780191
1882171
1984160
2085150
2186140
2287130
2388120
2489110
2590100
2690100
279190
289280
299370
309370

Wind in April

Winds average 8 km/h in April.

Across April, daily wind ranges from about 8 km/h on the calmest days to 8 km/h at its breeziest. It stays fairly steady from day to day.

051015151015202530
Wind speed (km/h)Feels
18calm
28calm
38calm
48calm
58calm
68calm
78calm
88calm
98calm
108calm
118calm
128calm
138calm
148calm
158calm
168calm
178calm
188calm
198calm
208calm
218calm
228calm
238calm
248calm
258calm
268calm
278calm
288calm
298calm
308calm

Sunrise & sunset in April

DaylightNight

Daylight runs from about 11 h 48 min at the start of April to 11 h 06 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 42 minutes over April. Sunrise moves from 6:24 AM to 6:38 AM, and sunset from 6:10 PM to 5:42 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
111.86:246:10
211.76:246:09
311.76:256:08
411.76:256:07
511.76:266:06
611.66:266:05
711.66:276:04
811.66:276:03
911.66:286:02
1011.56:286:01
1111.56:295:59
1211.56:295:58
1311.56:295:57
1411.46:305:56
1511.46:305:55
1611.46:315:54
1711.46:315:53
1811.36:325:52
1911.36:325:51
2011.36:335:50
2111.36:335:50
2211.26:345:49
2311.26:345:48
2411.26:355:47
2511.26:355:46
2611.26:365:45
2711.16:365:44
2811.16:375:43
2911.16:375:42
3011.16:385:42

Solar energy in April

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in April, about 4.8 kWh/m².

For context, solar energy here swings from a low near 3.91 kWh/m² to a high of 6.8 kWh/m² in December across the year — April's 4.8 kWh/m² falls in the middle.

0246151015202530
Solar energy (kWh/m²)Level
15.1Bright
25.0Bright
35.0Bright
45.0Bright
55.0Bright
65.0Bright
75.0Bright
85.0Bright
94.9Bright
104.9Bright
114.9Bright
124.9Bright
134.9Bright
144.8Bright
154.8Bright
164.8Bright
174.8Bright
184.8Bright
194.8Bright
204.7Bright
214.7Bright
224.7Bright
234.7Bright
244.6Bright
254.6Bright
264.6Bright
274.6Bright
284.6Bright
294.5Bright
304.5Bright
Planning a trip in April

Hazard calendar for Koster

In seasonPeak

None of Koster's seasonal hazards are active in April. The full-year calendar below shows when the rainy season, cyclone risk and dust haze do peak.

Koster's rainy season runs November–March, when most of the year's rain falls.

Rainy season
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec

Is April a good time to visit Koster?

Our two travel scores rate April for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal).

7.8
Sightseeing
6th-best month of the year
6.7
Beach & pool
3rd-best month of the year

April is one of the better times to visit Koster for general sightseeing. The water and warmth also suit a beach or pool day.

What to pack for Koster in April

From April's temperature range, rain chance, sun and wind — what's worth putting in the bag.

In April, Koster sees daytime highs around 24°C and nights near 13°C. Worth packing: light clothes and sun protection. About 7 days see rain.

light clothessun protection

UV index in Koster in April

LowModerateHighVery highExtreme

Clear-sky midday UV in April peaks around 9 (very high — sun protection essential). The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Koster peaks around January 13 at about 15 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near June 19 at about 5 (high).

The index reaches 3 or more — the level where the WHO recommends sun protection — every month of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecExtremeVery highHighVery highExtremeJan 13UV 15Jun 19UV 5
UV index (midday)Level
Jan15Extreme
Feb13Extreme
Mar12Extreme
Apr9Very high
May6High
Jun5High
Jul6High
Aug8Very high
Sep9Very high
Oct11Extreme
Nov12Extreme
Dec14Extreme

Air quality in Koster in April

GoodModeratePoorUnhealthyVery unhealthy

Average fine-particle pollution (PM2.5) through the year — so you can see where April falls, not just the annual average.

Air quality in Koster is worst in June — around 69 µg/m³ PM2.5 (unhealthy), about 5.0× the cleanest month (December, 14 µg/m³).

Modeled monthly averages (CAMS reanalysis, 2015–2024).

020406080JanFebMarAprMayJunJulAugSepOctNovDecModeratePoorUnhealthyPoorModerateJun 1869 µg/m³Dec 2114 µg/m³
PM2.5 (µg/m³)Level
Jan15Moderate
Feb22Moderate
Mar31Moderate
Apr46Poor
May62Unhealthy
Jun69Unhealthy
Jul66Unhealthy
Aug53Poor
Sep47Poor
Oct28Moderate
Nov17Moderate
Dec14Moderate
Location & terrain

Where is Koster?

Koster sits at 25.9°S, 26.9°E, 1,620 m above sea level, in South Africa. The nearest listed city is Rustenburg, 41 km away.

Topography around Koster

How much the land rises and falls, and what covers it, within 3, 16 and 80 km of Koster.

Within 3 km, the terrain around Koster has only modest variations in elevation — a maximum elevation change of 168 m around an average of 1,581 m above sea level; within 16 km, significant variations in elevation — a maximum elevation change of 397 m; within 80 km, large variations in elevation — a maximum elevation change of 868 m.

The land around Koster is covered by grassland (50%) and cropland (31%) within 3 km, grassland (54%) and cropland (26%) within 16 km, and grassland (58%) within 80 km.

3 km
168 m
16 km
397 m
80 km
868 m
treesshrubsgrasslandcroplandartificial surfaces
April weather nearby: Rustenburg 41 km · Ventersdorp 51 km · Marikana 61 km · Carletonville 75 km · Hartbeestfontein-A 77 km · Coligny 78 km · Bagale 78 km · Lichtenburg 80 km

South Africa travel facts

Travel advisory
Level 2
Exercise Increased Caution
Power plugs
Type C / M / N
230 V · 50 Hz
Prices
≈ 41% of US
price level, 2025
GDP per capita
$6,598
2025
Happiness
5.0 / 10
World Happiness, 2025
Safe drinking water
68%
of population, 2024
Homicide rate
43.7
per 100k, 2022
Road deaths
22.2
per 100k/yr, 2019
Income group
Upper middle
World Bank
English
Very high
EF EPI 602
Religion
Christian 86%or other traditional African religions 5%nothing in particular 5%Muslim 2%

Sources: World Bank, US State Department, World Happiness Report, WHO/UNICEF, EF EPI, CIA World Factbook.

Data sources

Temperature, precipitation, cloud, humidity, wind and solar figures are a 1991–2020 climatology for Koster (-25.863°, 26.8976°, elevation 1,620 m), computed from hourly ERA5 reanalysis — contains modified Copernicus Climate Change Service information. Sun figures are astronomical calculations, not observations. City data © GeoNames, CC BY 4.0. Map outlines from Natural Earth (public domain); interactive map © Google. UV index is derived from CAMS (Copernicus Atmosphere Monitoring Service) clear-sky UV data — contains modified Copernicus Atmosphere Monitoring Service information. Monthly air-quality (PM2.5) seasonality is from the CAMS EAC4 reanalysis (Copernicus Atmosphere Monitoring Service), scaled to the WHO annual mean where available. Topography is sampled from the Copernicus DEM GLO-90 elevation model (© ESA/Airbus) and ESA WorldCover 2021 land cover (CC BY 4.0).