Climate Insights for Johannesburg

The climate in Johannesburg is temperate. The average annual temperature is 17°C and approximately 705mm of precipitation falls per year. January is the wettest month, receiving around 128mm of rainfall. Johannesburg is in the Southern Hemisphere. The seasons are reversed — summer runs from December to February, while winter falls between June and August. The summer months are: December, November, October. The coldest months are July, June, August, when temperatures can drop to 3°C.

Temperatures in Johannesburg vary considerably across the year, with a 24°C difference between the coldest and warmest months. The warmest month is December, when average highs reach 27°C and the mean temperature sits around 21°C. July is the coolest month, with minimum temperatures around 3°C and an average of 10°C. On average, daily temperatures fluctuate by about 13°C between overnight lows and afternoon highs. The sharpest temperature change occurs between August and September, with a 4°C shift in average temperatures.

Johannesburg is a relatively dry area, receiving approximately 705mm of precipitation annually, which averages out to around 59mm per month. The wettest month is January, averaging 128mm of rainfall. December and February also tend to see above-average precipitation. The driest month is August, with just 2mm. That's 126mm less than January, the wettest month. Rainfall is heavily concentrated in certain months, creating a distinct wet and dry season. Visitors should plan around these patterns, as the difference between peak and low months is dramatic.

Johannesburg is mildly breezy, with an average annual wind speed of 17km/h. For context, sustained winds below 12km/h are generally light, while anything above 25km/h is considered strong. The windiest month is November, averaging 20km/h, though still comfortable for most outdoor activities. The calmest conditions occur in May, with average winds dropping to 14km/h, making it an ideal period for wind-sensitive activities. There is moderate seasonal variation in wind speed, with a 6km/h gap between the calmest and windiest months.

It is currently autumn in Johannesburg, which began on March 20, 2026. Johannesburg is in the Southern Hemisphere, where the seasons are reversed — spring starts in September, summer in December, autumn in March, and winter in June. The warmest period peaks in December at around 27°C, while the coldest stretch bottoms out in July near 3°C. Winter is next, beginning on June 21, 2026 — 90 days from now.

The best time to visit Johannesburg is during March, April, September, October and November, when the weather is most comfortable for travellers. During these months, average temperatures hover around 19°C with modest rainfall averaging 60mm per month. By contrast, December can be uncomfortably hot with highs reaching 27°C, while July is the coldest period with lows dropping to 3°C. A light rain jacket is recommended, though showers are generally brief and shouldn't disrupt your plans.

The table below shows monthly climate averages for Johannesburg based on historical weather data. Min and max temperatures represent typical overnight lows and afternoon highs for each month, shown in degrees Celsius (°C). Precipitation is measured in millimetres (mm) and indicates the average total rainfall per month. Wind speed is the average sustained speed in kilometres per hour (km/h). All values are based on averages from over 10 years of historical weather data. The current month is highlighted for quick reference.