Johannesburg weather in May
In May, Johannesburg has an average high of 19 °C67 °F and an average low of 4 °C40 °F, with about 16 mm0.6 in of precipitation. It is the 9th warmest month of the year and ranks 9th for precipitation.
How May compares with other months
Compared with April, May is 3.4 °C6 °F cooler on average and drier by 27 mm1.1 in. Compared with June, May is 3.3 °C5.9 °F warmer on average and wetter by 9 mm0.3 in. Daylight lasts about 10.8 hours around the middle of the month. Average relative humidity is 54% and the average cloud amount 30%.
Is May a good time to visit Johannesburg?
Yes — May is one of the most comfortable months to visit Johannesburg by our comfort score, which favours average highs of 21–28 °C, lows above 5 °C, little rain and moderate humidity.
What to wear in May
For Johannesburg in May, pack light layers — T-shirts plus a light sweater or jacket and an extra layer for the cooler mornings and evenings.
May in nearby places
| Place | High °C°F | Low °C°F | Precip. mmin |
|---|---|---|---|
| Johannesburg | 1967 | 440 | 160.6 |
| Alberton | 2169 | 541 | 150.6 |
| Roodepoort | 2067 | 440 | 160.6 |
| Soweto | 2069 | 541 | 150.6 |
| Thembisa | 2169 | 542 | 160.6 |
| Krugersdorp | 2068 | 540 | 160.6 |
| Etwatwa | 2169 | 541 | 120.5 |
| Nigel | 2169 | 541 | 110.4 |
| Pretoria | 2374 | 745 | 120.5 |
Nearby places that are more than 1 °C1.8 °F warmer in May: Alberton, Thembisa, Etwatwa and Pretoria.
Other months in Johannesburg
- January27 °C80 °F / 14 °C56 °F
- February27 °C80 °F / 13 °C56 °F
- March25 °C77 °F / 12 °C53 °F
- April22 °C72 °F / 8 °C47 °F
- May19 °C67 °F / 4 °C40 °F
- June16 °C61 °F / 1 °C34 °F
- July16 °C62 °F / 0 °C33 °F
- August20 °C68 °F / 3 °C38 °F
- September25 °C77 °F / 7 °C45 °F
- October27 °C80 °F / 10 °C50 °F
- November27 °C80 °F / 12 °C53 °F
- December27 °C80 °F / 13 °C56 °F
Frequently asked questions
How warm is Johannesburg in May?
In May the average high in Johannesburg is 19 °C (67 °F) and the average low is 4 °C (40 °F).
Does it rain a lot in Johannesburg in May?
On average about 16 mm (0.6 in) of precipitation falls in May; it ranks 9th of the 12 months.
Is May the warmest month in Johannesburg?
No. The warmest month in Johannesburg is November, with an average high of 27 °C (80 °F). The coldest month is July, with an average low of 0 °C (33 °F).
How long is the day in Johannesburg in May?
In the middle of May the day in Johannesburg lasts about 10.8 hours from sunrise to sunset. The value is calculated from the position of the city and the sun.
How humid is Johannesburg in May?
The average relative humidity in May is about 54%. This is a long-term average for the whole day.
How cloudy is Johannesburg in May?
On average about 30% of the sky is covered by cloud in May. This is the mean cloud amount from satellite data, not the number of sunny days.
About this data
All figures are 25-year averages (January 2001 – December 2025) from the NASA POWER project. Temperature, humidity, wind and precipitation come from the MERRA-2 reanalysis (precipitation is the bias-corrected MERRA-2 product), cloud and solar values from CERES satellite data. They describe a grid cell of roughly 50–70 km, not a single weather station, so they can differ from airport records — most of all on coasts, in mountains and for rainfall. Average highs and lows are the monthly mean temperature plus/minus half of the average daily temperature range. Counts of rainy days are not part of this dataset.
The grid cell’s average elevation is 1,538 m, while Johannesburg lies at about 1,767 m. Temperatures on this page were therefore adjusted by −1.5 °C2.7 °F using the standard lapse rate of 6.5 °C per 1,000 m.