Johannesburg climate — normals and trends
Johannesburg (South Africa) has a subtropical highland, dry winter climate (Cwb) under the Köppen-Geiger classification. Its mean annual temperature is 15.7 °C and it receives 800 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 (19.8 °C on average) and the coldest is June (9.2 °C). Rainfall peaks in December.
Johannesburg averages 7 frost days, 10 hot days (≥ 30 °C) and 114 rainy days per year.
Johannesburg has warmed by +1.3 °C between 1940 and 2025, or +0.15 °C per decade. This trend is statistically significant.
The hottest day of the period reached 37.0 °C (on 7 January 2016) and the coldest -5.5 °C (on 14 July 1990).
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
JohannesburgGauteng
- coords
- -26.20°, 28.04°
- period
- 1940–2025 · 86 yrs
Mean daily temperature
15.7°C
Average daily high
22.4°C
Average daily low
10.4°C
Annual rainfall
800mm
Sunshine / day
10.7h
Mean relative humidity
63%
Average peak wind
17.1km/h
Seasonal range
10.6°C
Frost days (< 0 °C)
7 d/yr
Hot days (≥ 30 °C)
10 d/yr
Rainy days (≥ 1 mm)
114 d/yr
Annual snowfall
0.2 cm
Average feels-like high
21.5 °C
Average feels-like low
8.3 °C
Average peak gust
35.5 km/h
Tropical nights (≥ 20 °C)
0 d/yr
Solar radiation
20.1 MJ/m²
Has the climate changed?
One stripe per year, 1940 to 2025
+1.3 °C
since 1940
+0.2 °C per decade · r² = 0.30 · p = < 0.001
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
37.0 °C
7 January 2016
Coldest day
-5.5 °C
14 July 1990
Wettest day
90 mm
27 September 1987
Windiest day
47.0 km/h
19 October 1945
Strongest gust
96.1 km/h
9 November 1940
Hottest feels-like
36.8 °C
7 January 2016
Coldest feels-like
-10.1 °C
14 July 1990
Snowiest day
11.6 cm
10 September 1981
Sunniest day
13.6 h
16 December 2025
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?
Across the whole year
Month by month
| High | vs. normal | Precipitation | vs. normal | |
|---|---|---|---|---|
| Jan | 26.0 °C | +0.7 °C | 250 mm | +111 mm |
| Feb | 24.8 °C | -0.1 °C | 277 mm | +158 mm |
| Mar | 24.0 °C | +0.1 °C | 171 mm | +79 mm |
| Apr | 20.7 °C | -1.0 °C | 127 mm | +70 mm |
| May | 20.1 °C | +0.5 °C | 7 mm | -13 mm |
| Jun | 17.8 °C | +0.7 °C | 2 mm | -6 mm |
| Jul | 17.9 °C | +0.5 °C | 10 mm | +6 mm |
| Aug | 22.3 °C | +2.0 °C | 13 mm | +3 mm |
| Sep | 25.2 °C | +1.3 °C | 38 mm | +13 mm |
| Oct | 25.0 °C | -0.1 °C | 82 mm | +7 mm |
| Nov | 22.4 °C | -2.5 °C | 198 mm | +86 mm |
| Dec | 24.2 °C | -1.0 °C | 188 mm | +46 mm |
The year's extremes
What was the weather like that day?
Your birthday, a wedding, a memorable trip: discover the actual weather for any date since 1940.
Frequently asked questions
What is the climate of Johannesburg?
Johannesburg has a subtropical highland, dry winter climate (Köppen Cwb). Over 1940-2025, the average annual temperature is 15.7 °C and it receives 800 mm of precipitation per year.
What is the hottest day ever recorded in Johannesburg?
The hottest day measured in Johannesburg between 1940 and 2025 was 7 January 2016, reaching 37.0 °C.
What is the coldest day in Johannesburg?
The coldest day measured in Johannesburg between 1940 and 2025 was 14 July 1990, at -5.5 °C.
Does it snow in Johannesburg?
Almost never: Johannesburg sees virtually no snow, with about 7 frost days per year.
Has the climate of Johannesburg warmed?
Yes: Johannesburg warmed by +1.3 °C between 1940 and 2025, a statistically significant trend.
What is the wettest day in Johannesburg?
The wettest day measured in Johannesburg between 1940 and 2025 was 27 September 1987, with 90 mm of rain in 24 hours.
What was the windiest day in Johannesburg?
The windiest day measured in Johannesburg between 1940 and 2025 was 19 October 1945, with winds reaching 47.0 km/h.
What is the warmest month in Johannesburg?
The warmest month in Johannesburg is January (19.8 °C on average); the coldest is June (9.2 °C).
How much does it rain in Johannesburg?
Johannesburg receives on average 800 mm of precipitation per year, spread over about 114 rainy days.
Is it sunny in Johannesburg?
Johannesburg gets on average 10.7 hours of sunshine per day, roughly 3,905 hours per year over 1940-2025.
What is the biggest single-day snowfall in Johannesburg?
The heaviest 24-hour snowfall measured in Johannesburg between 1940 and 2025 was 10 September 1981, with 11.6 cm.
Are there tropical nights in Johannesburg?
Almost never: tropical nights (temperature staying above 20 °C) are virtually non-existent in Johannesburg.
What was the most extreme apparent temperature in Johannesburg?
In Johannesburg, between 1940 and 2025, the highest apparent temperature reached 36.8 °C on 7 January 2016, and the lowest was -10.1 °C on 14 July 1990.
Compare Johannesburg with another city
Pick a second city: its normals will be set against these, indicator by indicator.
Nearby cities
The climate around Johannesburg