Climate and average weather in Randfontein

In Randfontein, the summers are warm, wet, and partly cloudy and the winters are mild and clear.

Best: early April to mid October

Over the course of the year, the temperature in Randfontein typically varies from 4°C to 26°C, and is rarely below 0°C or above 31°C. January is the hottest month of the year, while June is the coldest.

Based on the travel score, the best time of year to visit Randfontein for warm-weather activities is from early April to mid October.

Hottest
Jan
26°
Coldest
Jun
Wettest
Dec
141 mm
Driest
Jul
3 mm
Rain / yr
757 mm
105 wet days
Daylight
10.4–13.6 h
shortest–longest
Elevation
1,716 m
26.2°S
Clearest
Jul
13% cloud

Randfontein is town.

Founded
1890

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

Randfontein weather by month, at a glance

The whole year in one picture — sky, rain, humidity, temperature and travel score. Click any band to jump to its full chart.

Each stripe is one measure across the whole year, stacked so a single day reads top to bottom. The sky band runs overcast grey on top down to clear blue at the base — more blue means sunnier — followed by the rainfall curve, the humidity band, a temperature strip that tints each stretch of the year by how warm its average high is, and the travel-score line at the foot. Scan straight down any date to read that day across every measure at once; the score climbs highest around early April to mid October.

Temperature through the year

Average highAverage lowShaded bands: 10–90% of days

Daily average highs and lows in Randfontein, from 1991–2020 of climate data. The shaded bands show the range most days fall in — 10th to 90th percentile.

The hot season lasts 6.5 months, from September 8 to March 25, with daily high temperatures above 24°C. The hottest month of the year in Randfontein is January, with an average high of 26°C and low of 16°C.

The cool season lasts 2.1 months, from May 29 to August 1, with daily high temperatures below 19°C. The coldest month of the year in Randfontein is June, with an average low of 4°C and high of 18°C.

Days typically run about 12°C warmer than nights, with the widest day–night swing (around 14°C) in July.

10°20°30°JanFebMarAprMayJunJulAugSepOctNovDec
Avg high (°C)Avg low (°C)
Jan2616
Feb2616
Mar2414
Apr2211
May207
Jun184
Jul184
Aug217
Sep2410
Oct2513
Nov2614
Dec2615

Average hourly temperature in Randfontein

A compact picture of the whole year, hour by hour: each column is a day, each row an hour, and the color is the modeled average temperature. Darker overlays mark night, lighter ones the civil-twilight hours around sunrise and sunset.

Read left to right for the day of the year and top to bottom for the hour of the day; the color is the modeled temperature, cool blues through to hot reds on the same scale as the other charts. A vertical slice is a single day's swing — coolest just before dawn, warmest in the mid-afternoon — while a horizontal slice follows one hour across the seasons. The darker overlay marks night and the lighter one the twilight around sunrise and sunset. Colors run warmest on January afternoons, near 26°C, and coldest before dawn in June, near C.

JanFebMarAprMayJunJulAugSepOctNovDec12 AM2 AM4 AM6 AM8 AM10 AM12 PM2 PM4 PM6 PM8 PM10 PM12 AM

Randfontein weather by month

Every month at a glance. Click a month for its detailed page.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan26° / 16°13216.913.55.8
Feb26° / 16°11714.212.96.1
Mar24° / 14°9012.812.26.7
Apr22° / 11°457.411.47.4
May20° / 183.110.78.1
Jun18° / 81.410.47.9
Jul18° / 30.810.58.0
Aug21° / 101.911.18.5
Sep24° / 10°213.411.88.6
Oct25° / 13°7310.412.67.1
Nov26° / 14°9913.913.36.2
Dec26° / 15°14118.513.65.6

Chance of rain

How likely it is to rain on a typical day, and how that shifts across the wetter and drier seasons.

Randfontein gets about 757 mm of precipitation a year. On a typical day the chance of rain is some rain, but that rises and falls sharply with the seasons.

The wetter season lasts 5.9 months, from around Oct 10 to Apr 8, peaking in December at about 60% chance on a given day. The drier stretch runs the rest of the year, bottoming out around Jul 12.

December is the wettest month by volume, with 141 mm over about 19 wet days; July is the driest, with 3 mm.

0%10%20%30%40%50%60%70%JanFebMarAprMayJunJulAugSepOctNovDecwetterdrierwettermostly drysome rainoften wetvery wetDec 13 · 60%Jul 12 · 2%
Rain on a day (%)Rain days
Jan5417
Feb5014
Mar4213
Apr257
May103
Jun51
Jul31
Aug62
Sep123
Oct3310
Nov4714
Dec5819

Monthly rainfall

Over a full year, Randfontein collects about 757 mm of rain across 105 wet days — roughly 63 mm in an average month.

It doesn’t fall evenly. December is the wettest month with 141 mm, while July is the driest at just 3 mm. The three wettest months alone bring about 52% of the year’s total.

0255075100125150175JanFebMarAprMayJunJulAugSepOctNovDec1321179045188310217399141
Rainfall (mm)Rain days
Jan13217
Feb11714
Mar9013
Apr457
May183
Jun81
Jul31
Aug102
Sep213
Oct7310
Nov9914
Dec14119

Clouds and sunshine

ClearMostly clearPartly cloudyMostly cloudyOvercast

How often the daytime sky is clear, partly cloudy or overcast.

In Randfontein, the average share of the sky covered by clouds shows significant seasonal variation over the course of the year.

The clearer part of the year begins around April 16 and lasts for 5.8 months, ending around October 9. The clearest month is July, when the sky is clear, mostly clear, or partly cloudy 93% of the time on average.

The cloudier part of the year begins around October 10 and lasts for 6.2 months, ending around April 15. The cloudiest month is December, when it is overcast or mostly cloudy 44% of the time.

0%100%10%90%20%80%30%70%40%60%50%50%60%40%70%30%80%20%90%10%100%0%JanFebMarAprMayJunJulAugSepOctNovDecJul 21 · 94%Nov 29 · 54%clearmostly clearpartly cloudymostly cloudyovercastcloudierclearercloudier
Clearer (%)Cloudier (%)
Jan5941
Feb6436
Mar6832
Apr7525
May8614
Jun919
Jul937
Aug9010
Sep8515
Oct7228
Nov5842
Dec5644

Daylight, sunrise and sunset

DaylightNight

Hours of daylight through the year, with sunrise and sunset times.

The gold band is daylight — sunrise runs along its lower edge, sunset along the upper — so it widens toward summer and pinches toward winter, with night the dark area above and below. The longest day, around January 1, brings about 13 h 36 min of light; the shortest, around June 5, only 10 h 24 min — a swing of roughly 3 h 12 min.

12 AM4 AM8 AM12 PM4 PM8 PM12 AMJanFebMarAprMayJunJulAugSepOctNovDec
Daylight (h)Sunrise (AM)Sunset (PM)
Jan13.55:347:03
Feb12.95:566:51
Mar12.26:136:25
Apr11.46:285:51
May10.76:445:27
Jun10.46:585:21
Jul10.57:005:30
Aug11.16:415:45
Sep11.86:085:59
Oct12.65:356:13
Nov13.35:156:34
Dec13.65:166:54

Sunny days

How many genuinely sunny days each month brings — days the sky stays clear or mostly clear — banded into plain-language zones.

Randfontein averages about 17 sunny days a month — counting the days the sky stays clear or mostly clear — with a clear seasonal swing between 9 and 26 days.

The sunnier stretch runs 5.5 months, from around Apr 20 to Oct 3. The sunniest month is July, with roughly 26 sunny days (brilliant).

The greyest month is December, down near 9 sunny days — about 65% fewer than the July peak.

051015202530JanFebMarAprMayJunJulAugSepOctNovDecgreyersunniergreyergloomymixedbrightbrilliantJul 2426 daysDec 159 days
Sunny daysSky
Jan11Mixed
Feb11Mixed
Mar14Mixed
Apr17Bright
May23Bright
Jun25Brilliant
Jul26Brilliant
Aug26Brilliant
Sep22Bright
Oct16Bright
Nov11Mixed
Dec9Mixed

Humidity comfort

DryComfortableHumidMuggyOppressiveMiserable

Share of days at each humidity comfort level, based on the dew point — the measure that tracks how muggy it actually feels.

Humidity comfort is graded by the dew point — the temperature at which the air would be fully saturated — because it tracks how muggy it actually feels far better than relative humidity does. A low dew point feels dry and crisp; a high one feels sticky and oppressive no matter the reading on a humidity gauge.

In Randfontein, how humid it feels changes dramatically over the year.

The more humid part of the year lasts 3.5 months, from around December 4 to March 20. The muggiest month is January, when the air feels humid, muggy or worse about 33% of the time.

The most comfortable stretch runs from around March 21 to December 3, and April is the most comfortable month — the air is dry or comfortable 99% of the time.

0%10%20%30%40%50%60%70%80%90%100%JanFebMarAprMayJunJulAugSepOctNovDecApr 24 · 100%Jan 23 · 64%humidcomfortabledryhumidcomfortablehumid
Dry (%)Comfortable (%)Humid (%)
Jan204733
Feb244728
Mar484110
Apr89101
May10000
Jun10000
Jul10000
Aug10000
Sep10000
Oct9280
Nov65323
Dec325216

Wind

Average wind speed through the year, banded into plain-language speed zones so a number reads as 'breezy' or 'calm' without knowing the scale.

This is the average sustained wind speed at the standard 10 metres above open ground — the steady flow a weather station reports, not the sharper gusts that come and go, which can run half again as fast. It's the number that says whether a place is generally breezy or calm.

Across the year, average wind speed in Randfontein is typically calm, near 11 km/h, and varies little with the seasons.

The windier part of the year lasts 5.0 months, from around Jul 27 to Dec 26. The windiest month is September, averaging about 12 km/h (light breeze).

The calmer part of the year runs from around Dec 27 to Jul 26, with March the calmest month at about 9 km/h.

05101520JanFebMarAprMayJunJulAugSepOctNovDeccalmerwindiercalmlight breezeSep 27 · 13 km/hMar 26 · 9 km/h
Wind speed (km/h)Feels
Jan10calm
Feb9calm
Mar9calm
Apr9calm
May9calm
Jun10calm
Jul10calm
Aug12calm
Sep12light breeze
Oct13light breeze
Nov12light breeze
Dec11calm

Hazard calendar for Randfontein

In seasonPeak

When the seasonal hazards worth planning around — the rainy season, tropical-cyclone risk and dust haze — are active through the year.

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

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

Best time to visit Randfontein

TravelBeach/poolTemperatureCloudsPrecipitation

To characterize how pleasant the weather is in Randfontein throughout the year, we compute two travel scores — one for general sightseeing, one for beach and pool weather.

Around mid April, Randfontein is still near the start of its best-weather window — great conditions with the peak-season crowds not yet at full swing.

Inferred from the travel-score curve; month-by-month visitor numbers are a planned addition.

The travel score favors clear, rainless days with daytime highs between 18°C and 28°C. Based on this score, the best time of year to visit Randfontein for general outdoor tourist activities is from early April to mid October, with a peak score in the first week of September.

0246810JanFebMarAprMayJunJulAugSepOctNovDecbest timetravel scoretemperaturecloudsprecipitationSep 5 · 8.9

The travel score (filled area), and its constituents: the temperature score (red line), the cloud cover score (blue line), and the precipitation score (green line).

Travel score (0–10)Rating
Jan5.8good
Feb6.1good
Mar6.7good
Apr7.4good
May8.1ideal
Jun7.9ideal
Jul8.0ideal
Aug8.5ideal
Sep8.6ideal
Oct7.1good
Nov6.2good
Dec5.6good

The beach/pool score favors clear, rainless days with daytime highs between 24°C and 34°C. Based on this score, the best time of year to visit Randfontein for hot-weather activities is from late August to early November, with a peak score in the third week of September.

024681012JanFebMarAprMayJunJulAugSepOctNovDecbest timebeach/pool scoretemperaturecloudsprecipitationSep 15 · 7.5

The beach/pool score (filled area), and its constituents: the temperature score (red line), the cloud cover score (blue line), and the precipitation score (green line).

What to pack for Randfontein, by month

EssentialRecommendedOptional

Month by month, what's worth putting in the bag — from the temperature range, rain chance, sun and wind. Tap a month for a quick packing note.

For a warm-season trip around January (highs near 26°C), the essentials are light clothes, rain gear and sun protection. In the cold season around June (highs near 18°C), pack a warm layer.

Light clothing
Warm layer
Winter coat
Rain gear
Sun protection
Windbreaker

In January, Randfontein sees daytime highs around 26°C and nights near 16°C. Pack rain gear and sun protection. Worth having: light clothes. About 17 days see rain.

UV index (midday) in Randfontein by month

LowModerateHighVery highExtreme

Clear-sky midday UV index through the year, shaded by the WHO exposure levels — how much sun protection each month calls for.

Under clear skies, the midday UV index in Randfontein peaks around January 11 at about 14 (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 11UV 14Jun 19UV 5
UV index (midday)Level
Jan14Extreme
Feb13Extreme
Mar12Extreme
Apr9Very high
May6High
Jun5High
Jul6High
Aug7Very high
Sep9Very high
Oct11Extreme
Nov12Extreme
Dec14Extreme

Average hourly UV index in Randfontein

LowModerateHighVery highExtreme

Modeled clear-sky UV for every hour of every day — when in the day sun protection actually matters.

The whole year hour by hour: each column is a day, each row an hour, and the color is the modeled clear-sky UV index — the midday peak scaled down as the sun sits lower in the sky. Darker overlays mark night, lighter ones the civil-twilight hours around sunrise and sunset.

UV falls off far faster than brightness as the sun drops, so even in January the burn window is concentrated in the middle of the day: about 9 hours a day reach index 3 (protection recommended), and 7 hours reach 6 or more. Mornings and late afternoons stay comparatively gentle year round.

JanFebMarAprMayJunJulAugSepOctNovDec12 AM2 AM4 AM6 AM8 AM10 AM12 PM2 PM4 PM6 PM8 PM10 PM12 AM
UV ≥ 3 (h/day)UV ≥ 6 (h/day)
Jan97
Feb8.56.5
Mar86
Apr6.54
May5.51
Jun4.50
Jul50
Aug63
Sep74.5
Oct85.5
Nov8.56.5
Dec97

Air quality in Randfontein by month

GoodModeratePoorUnhealthyVery unhealthy

Average fine-particle pollution (PM2.5) through the year — so you can see which months the air is worst, not just the yearly average.

Air quality in Randfontein is worst in June — around 283 µg/m³ PM2.5 (very unhealthy), about 5.7× the cleanest month (January, 50 µg/m³).

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

0306090120150180210240270300JanFebMarAprMayJunJulAugSepOctNovDecUnhealthyVery unhealthyUnhealthyJun 19282 µg/m³Jan 1251 µg/m³
PM2.5 (µg/m³)Level
Jan50Poor
Feb72Unhealthy
Mar119Unhealthy
Apr177Very unhealthy
May261Very unhealthy
Jun283Very unhealthy
Jul275Very unhealthy
Aug213Very unhealthy
Sep156Very unhealthy
Oct99Unhealthy
Nov70Unhealthy
Dec55Poor
Almanac & agriculture

Growing season

Chance of a frost-free dayReliably frost-free (≥90%)

Randfontein is mild enough that a frost-free day stays more likely than not even in midwinter. Nights are reliably above freezing from about July 12 to July 4 (358 days); outside that window a hard frost is an occasional risk.

0%25%50%75%100%JanFebMarAprMayJunJulAugSepOctNovDecreliably frost-freereliably frost-freeJul 1290%Jul 490%
Frost-free chance (%)Frost nights
Jan1000
Feb1000
Mar1000
Apr1000
May1000
Jun950
Jul925
Aug980
Sep1000
Oct1000
Nov1000
Dec1000

Growing degree days

Degree days (base 10°C)Frost-free shaded

Growing degree days tally heat above 10°C: each day adds however many degrees its average temperature runs over that threshold, and cold days add nothing. Randfontein banks about 2,526 degree days a year, and the running total — which growers use to time plantings and predict maturity — climbs fastest around January.

01,0002,000JanFebMarAprMayJunJulAugSepOctNovDec
Growing degree days (°C·days)
Jan337
Feb296
Mar286
Apr199
May116
Jun30
Jul25
Aug113
Sep222
Oct284
Nov293
Dec325

Solar energy

Average daily shortwave solar energy reaching the ground, banded into brightness zones so the number means something at a glance.

Solar energy is how much sunlight actually reaches the ground each day, measured in kilowatt-hours per square metre (kWh/m²) — the combined effect of how long the sun is up, how high it climbs, and how much cloud gets in the way. It's the raw fuel a solar panel has to work with: for scale, 1 kWh/m² a day is dim and wintry, while 7+ is desert-bright.

Randfontein receives about 5.6 kWh/m² a day of solar energy on average — bright — with a clear seasonal swing between 3.9 and 6.9 kWh/m².

The brighter stretch of the year lasts 6.4 months, from around Sep 1 to Mar 14. The brightest month is December, averaging about 6.9 kWh/m² (intense).

The dimmest month is June, down near 3.9 kWh/m² — roughly 43% less than the December peak.

012345678JanFebMarAprMayJunJulAugSepOctNovDecbrighterdimmerbrighterdimmoderatebrightintenseDec 206.9 kWhJun 203.9 kWh
Solar energy (kWh/m²)Level
Jan6.7Intense
Feb6.3Intense
Mar5.6Bright
Apr4.8Bright
May4.3Bright
Jun3.9Moderate
Jul4.2Bright
Aug5.0Bright
Sep6.1Intense
Oct6.6Intense
Nov6.8Intense
Dec6.9Intense

Where is Randfontein?

Randfontein sits at 26.2°S, 27.7°E, 1,716 m above sea level, in South Africa. The nearest listed city is Krugersdorp, 13 km away.

Topography around Randfontein

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

Within 3 km, the terrain around Randfontein has only modest variations in elevation — a maximum elevation change of 105 m around an average of 1,705 m above sea level; within 16 km, significant variations in elevation — a maximum elevation change of 364 m; within 80 km, large variations in elevation — a maximum elevation change of 900 m.

The land around Randfontein is covered by grassland (46%) and artificial surfaces (40%) within 3 km, grassland (57%) within 16 km, and grassland (56%) within 80 km.

3 km
105 m
16 km
364 m
80 km
900 m
treesshrubsgrasslandcroplandartificial surfacesbare terrain
Nearby: Krugersdorp 13 km · Bagale 14 km · Westonaria 16 km · Roodepoort 17 km · Soweto 18 km · Randburg 32 km · Johannesburg 34 km · Carletonville 36 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 Randfontein (-26.1844°, 27.702°, elevation 1,716 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).