Koster in Fall

In fall (March, April and May), Koster sees average daytime highs around 24°C and overnight lows near 13°C, with 130 mm of rain over about 20 wet days across the season. It is the 3rd-warmest season and the 3rd-wettest season.

Over the season highs ease from about 27°C in early March to 21°C by late May. The sky is clear or mostly clear about 62% of the time across fall, and the air most often feels dry.

Fall is Koster's 2nd-best season to visit on our travel score. For the whole year in context, see Koster's year-round climate.

Avg daytime high
24°C
3rd-warmest season
Avg overnight low
13°C
Rainfall
130 mm
20 wet days
Avg wind
8 km/h
Travel score
7.7
2nd-best season
Months
Mar · Apr · May

Temperature in Koster in Fall

Average highAverage lowShaded bands: 10–90% of days

Over the season highs ease from about 27°C in early March to 21°C by late May.

A typical fall day in Koster reaches about 24°C and drops to 13°C overnight. The warmest of the three months is March, the coolest May.

10°20°30°MarAprMay

Koster weather by month

How the three fall months (March, April and May) compare with the rest of the year — the season's months are highlighted.

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 Fall

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 62% of the time across fall.

0%25%50%75%100%MarAprMay

Chance of precipitation in Fall

Any precipitation

Koster gets around 130 mm of rain over 20 wet days across fall. The line is the day-by-day chance of measurable precipitation.

0%10%20%30%40%50%MarAprMay

Humidity in Fall

DryComfortableHumidMuggyOppressiveMiserable

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

0%25%50%75%100%MarAprMay

Wind in Fall

Winds average 8 km/h across fall.

051015MarAprMay

Sunrise & sunset in Fall

DaylightNight

Daylight runs from about 12 h 36 min in early March to 10 h 30 min by late May. The lit band spans sunrise to sunset each day.

12 AM4 AM8 AM12 PM4 PM8 PM12 AMMarAprMay

Solar energy in Fall

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day across fall, about 4.9 kWh/m².

0246MarAprMay
Planning a trip in fall

Hazard calendar for Koster

In seasonPeak

In fall, Koster overlaps its rainy season season. The full year is below, with each hazard's peak months called out.

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 fall a good time to visit Koster?

Our two travel scores rate fall for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal), averaged across the three months.

7.7
Sightseeing
2nd-best month of the year
6.5
Beach & pool
2nd-best month of the year

fall 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 Fall

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

In fall, Koster sees daytime highs around 24°C and nights near 13°C. Worth packing: light clothes, rain gear and sun protection. About 20 days see rain.

light clothesrain gearsun protection

UV index in Koster in Fall

LowModerateHighVery highExtreme

Clear-sky midday UV across fall averages 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 Fall

GoodModeratePoorUnhealthyVery unhealthy

Average fine-particle pollution (PM2.5) through the year — so you can see where fall 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
Fall 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.