Weather in Johannesburg in August

Prime time. If you get to pick your dates, August is the one. Highs average 21 °C, lows 4 °C, and rain falls on 1 days — nothing in the month is working against you.

August is the highest-scoring month of the twelve. The nearest rival is May, and the month at the other end of the year is December.

Rain falls on only 1 days, so an itinerary with no wet-weather fallback is a reasonable risk. Nothing specialised needed — this is the month you pack for the trip rather than for the weather.

What the averages hide

Averages flatten a month, and this one hides a few things: it never really gets hot: not one day in an average August reaches 30 °C; 3 nights fall below freezing; the day swings 17 °C from low to high, which means one bag has to cover both. Across the twenty years measured, the hottest August day reached 28.3 °C and the coldest night fell to -5.7 °C.

August is dependably dry, and that reliability is the point: across the twenty years measured, the wettest August on record still only managed 30 mm, and the driest managed 0 mm. There is no meaningful variability to plan around, which makes this one of the few months anywhere that you can build a fixed outdoor itinerary against without a fallback. The wettest single day in twenty years of Augusts brought 15 mm. Rain simply is not the variable that decides this trip — heat, crowds and cost are.

Wind is light at 10 km/h, so the temperature on the page is close to the temperature on your skin, and humidity is unremarkable at 44%.

How August sits in the year

The month is on the way up: 3.5 °C warmer than July, and September adds another 4.4 °C. Late in the month feels noticeably different from the start of it, which is worth knowing if the trip is short.

Daylight in August

11.2 hours of daylight, gaining 0.6 hours across the month. That is between Johannesburg's extremes of 13.8 and 10.5 hours, so days are long enough not to constrain the plan.

An inland climate

With no coast nearby, the year swings a fair way — 25.6 °C between the warmest afternoons and the coldest nights, wider than any coastal city at this latitude would manage. At 1767 m, altitude is doing as much work here as latitude: thinner air means fierce sun by day and heat that leaves the moment it sets. Within August itself the daily swing is 17 °C, so mornings and afternoons need different clothes.

How busy it gets

Peak season. Expect the highest prices of the year and to be booking well ahead. If the dates are flexible, April is the trade worth considering — 12 points weaker on weather, and materially quieter.

Crowd levels are estimated from climate desirability and school-holiday calendars, not from visitor numbers.

August in Johannesburg versus nearby

If Johannesburg is one option among several, the nearby comparison is worth making. Pretoria is close enough to be a coin toss — 3.6 °C warmer, the same number of rain days. Pietermaritzburg is the weaker option in August — 2.8 °C warmer, 5 days more rain.

So: August is the answer for Johannesburg. If it is booked out or priced out, May is the next best thing at 1 points behind, and December is the month to keep off the shortlist.

Every month in Johannesburg

See all twelve months in Johannesburg, or where else to go in August.