Sydney
Australia
Long-term weather forecast
Long-term weather forecast

December weather forecast and climate
Sydney, Australia

The landmarks of the city of Sydney, Australia viewed from above the vast Parramatta River
The landmarks of the city of Sydney, Australia viewed from above the vast Parramatta River
The first month of the summer, December, is still a warm month in Sydney, Australia, with average temperature fluctuating between 25.2°C (77.4°F) and 17.5°C (63.5°F).

Temperature

In December, the average high-temperature is practically the same as in November - a still moderately hot 25.2°C (77.4°F). In Sydney, the average low-temperature is 17.5°C (63.5°F).

Humidity

In December, the average relative humidity in Sydney, Australia, is 59%.

Rainfall

In December, in Sydney, the rain falls for 11.5 days. Throughout December, 77.6mm (3.1") of precipitation is accumulated. Throughout the year, in Sydney, there are 143.4 rainfall days, and 1212.1mm (47.7") of precipitation is accumulated.

Sea temperature

In Sydney, Australia, the average seawater temperature is 21.9°C (71.4°F). For swimming, a surface water temperature of 21.9°C (71.4°F) is not enjoyable for the majority. It is not considered safe, as controlling breathing becomes progressively more difficult as water temperature decreases below 21°C (69.8°F).

Daylight

With an average of 14.4h of daylight, December has the longest days of the year in Sydney.

Sunshine

August through October and December, with an average of 7.9h of sunshine, are months with the most sunshine.

UV index

January and December, with an average maximum UV index of 12, are months with the highest UV index. A UV Index value of 11, and more, symbolizes an ultimate health vulnerability from the exposure to the Sun's UV rays for the ordinary person.
The average daily UV index of 12 transform into the following instructions:
Take all required precautions, as unprotected skin and eyes can burn in minutes. The Sun's UV radiation is most powerful between 10 a.m. and 4 p.m. To the extent possible, limit exposure to the direct sun during these hours. A wide-brim hat offers excellent sun protection for eyes, ears, face, and neck. Sunglasses with UVA and UVB protection significantly reduce eye damage from sun exposure. Tightly woven, loose-fitting clothes provide additional protection from the Sun. Prolonged stay under the direct sun should be avoided as much as possible, especially if a person burns easily. Sunscreen with a minimum 30 sun protection factor should always be used. Caution! The reflection of sand and water significantly increases the intensity of the Sun's UV radiation.

What is the temperature in December in Sydney?

The average high-temperature, in December, in Sydney, Australia, is 25.2°C (77.4°F), while the average low-temperature is 17.5°C (63.5°F).

What is the average humidity in December in Sydney?

In December, the average relative humidity in Sydney, Australia, is 59%.

How much does it rain in Sydney in December?

In Sydney, in December, during 11.5 rainfall days, 77.6mm (3.1") of precipitation is typically accumulated.

What is the sea water temperature in December in Sydney?

In Sydney, Australia, in December, the average water temperature is 21.9°C (71.4°F). Swimming in 21.9°C (71.4°F) is not enjoyable for the majority. Controlling breathing becomes progressively more difficult as surface water temperature decreases below 21°C (69.8°F).

When are the longest days in Sydney?

December has the longest days of the year, with an average of 14.4h of daylight.

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

In December, the average length of the day in Sydney is 14.4h.

What is the month with the most sunshine in Sydney?

August through October and December, with an average of 7.9h of sunshine, are months with the most sunshine in Sydney, Australia.

How long on average sun shines in December in Sydney?

The average sunshine in December in Sydney is 7.9h.

What is the month with the highest UV index in Sydney?

January and December, with an average maximum UV index of 12, are months with the highest UV index in Sydney, Australia.

What is the UV index reading in December in Sydney?

In December, the average daily maximum UV index is 12. A UV Index estimate of 11, and higher, represents an extreme health vulnerability from the exposure to the Sun's UV rays.
Average temperature in December - Sydney, Australia
  • Average high temperature in December: 25.2°C

The warmest month (with the highest average high temperature) is January (25.9°C).
The month with the lowest average high temperature is July (16.3°C).

  • Average low temperature in December: 17.5°C

The month with the highest average low temperature is February (18.8°C).
The coldest month (with the lowest average low temperature) is July (8.1°C).

Average humidity in December - Sydney, Australia
  • Average humidity in December: 59%

The month with the highest relative humidity is February (64%).
The month with the lowest relative humidity is August (49%).

Average rainfall in December - Sydney, Australia
  • Average rainfall in December: 77.6mm

The wettest month (with the highest rainfall) is June (131.9mm).
The driest month (with the lowest rainfall) is September (68.3mm).

Average rainfall days in December - Sydney, Australia
  • Average rainfall days in December: 11.5 days

The month with the highest number of rainy days is March (13.6 days).
The month with the lowest number of rainy days is August (10.4 days).

Average sea temperature in December - Sydney, Australia
  • Average sea temperature in December: 21.9°C

The best month for swimming (with the highest average sea temperature) is February (23.7°C).
The coldest month (with the lowest average sea temperature) is September (18.6°C).

Average daylight in December / Average sunshine in December - Sydney, Australia
  • Average daylight in December: 14.4h

The month with the longest days is December (Average daylight: 14.4h).
The month with shortest days is June (Average daylight: 9.9h).

  • Average sunshine in December: 7.9h

Months with most sunshine are August, September, October and December (Average sunshine: 7.9h).
The month with least sunshine is June (Average sunshine: 5.9h).

Average UV index in December - Sydney, Australia
  • Average UV index in December: 12

Months with the highest UV index are January and December (UV index 12).
The month with the lowest UV index is June (UV index 2).