Johannesburg
South Africa
Long-term weather forecast
Long-term weather forecast

December weather forecast and climate
Johannesburg, South Africa

The vast cityscape of Gauteng Province in Johannesburg, South Africa
The vast cityscape of Gauteng Province in Johannesburg, South Africa
December is a warm summer month in Johannesburg characterized by high temperatures between 14°C (57.2°F) and 25°C (77°F) and a rise in humidity to an average of 63%.
Rainfall is high, and it falls for approximately seventeen days across the month to collect at 109.2mm (4.3"). It is accompanied by thunderstorms and flashes of lightning, and the mornings may be a little chilly as opposed to the warmer and cooler evenings. During the day, the sun will shine for an average of eleven hours.

What is the temperature in December in Johannesburg?

In Johannesburg, in December, the average high-temperature is 25.2°C (77.4°F), and the average low-temperature is 13.9°C (57°F).

What is the average humidity in December in Johannesburg?

In December, the average relative humidity in Johannesburg, South Africa, is 66%.

How many days does it rain in December in Johannesburg?

In Johannesburg, South Africa, in December, during 14.9 rainfall days, 105mm (4.1") of precipitation is typically accumulated.

When are the longest days in Johannesburg?

The month with the longest days in Johannesburg, South Africa, is December, with an average of 13.8h of daylight.

What is the average length of the day in December in Johannesburg?

In December, the average length of the day in Johannesburg, South Africa, is 13.8h.

How many hours of sunshine does Johannesburg have in December?

In December, the average sunshine in Johannesburg is 8.5h.

When is the highest UV index in Johannesburg?

January through March, November and December, with an average maximum UV index of 12, are months with the highest UV index.

How high is the UV index in December in Johannesburg?

The average daily maximum UV index in December is 12. A UV Index estimate of 11, and higher, represents an ultimate hazard to health from the exposure to the Sun's UV rays.
Average temperature in December - Johannesburg, South Africa
  • Average high temperature in December: 25.2°C

The warmest month (with the highest average high temperature) is January (25.6°C).
The month with the lowest average high temperature is June (16°C).

  • Average low temperature in December: 13.9°C

The month with the highest average low temperature is January (14.7°C).
Coldest months (with the lowest average low temperature) are June and July (4.1°C).

Average humidity in December - Johannesburg, South Africa
  • Average humidity in December: 66%

The month with the highest relative humidity is February (70%).
The month with the lowest relative humidity is August (46%).

Average rainfall in December - Johannesburg, South Africa
  • Average rainfall in December: 105mm

The wettest month (with the highest rainfall) is January (125mm).
The driest month (with the lowest rainfall) is July (4mm).

Average rainfall days in December - Johannesburg, South Africa
  • Average rainfall days in December: 14.9 days

The month with the highest number of rainy days is January (15.9 days).
The month with the lowest number of rainy days is July (1 days).

Average daylight in December / Average sunshine in December - Johannesburg, South Africa
  • Average daylight in December: 13.8h

The month with the longest days is December (Average daylight: 13.8h).
The month with shortest days is June (Average daylight: 10.5h).

  • Average sunshine in December: 8.5h

The month with most sunshine is September (Average sunshine: 9.4h).
The month with least sunshine is March (Average sunshine: 7.7h).

Average UV index in December - Johannesburg, South Africa
  • Average UV index in December: 12

Months with the highest UV index are January, February, March, November and December (UV index 12).
Months with the lowest UV index are June and July (UV index 5).