December weather forecast and climate
Sydney, Australia

The landmarks of the city of Sydney, Australia
The landmarks of the city of Sydney, Australia
The first month of the summer, December, is also a moderately hot month in Sydney, Australia, with average temperature ranging between min 17.5°C (63.5°F) and max 25.2°C (77.4°F).

Temperature

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

Humidity

In Sydney, the average relative humidity is 59%.

Rainfall

In Sydney, it is raining for 11.5 days, with typically 77.6mm (3.06") of accumulated precipitation. In Sydney, during the entire year, the rain falls for 143.4 days and collects up to 1212.1mm (47.72") of precipitation.

Sea temperature

In December, the average sea temperature is 21.9°C (71.4°F).
Note: 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

The month with the longest days in Sydney is December, with an average of 14.4h of daylight.

Sunshine

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

UV index

Months with the highest UV index are January and December, with an average maximum UV index of 12. A UV Index value of 11, and more, symbolizes an excessive health risk from unsafe exposure to the UV radiation for average individuals.
Note: In December, the average maximum UV index of 12 translate into the following recommendations:
Take all required precautions, as unprotected skin and eyes can burn in minutes. Seek shade and minimize exposure to direct Sun in a period between 10 a.m. and 4 p.m. when UV radiation is most intense; keep in mind that shade structures like parasols or canopies do not provide perfect sun protection. 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. Beware! The strength of the UV rays is significantly increased by the reflection of the water and sand.

What is the temperature in December in Sydney?

In December, the average high-temperature is 25.2°C (77.4°F), and the average low-temperature is 17.5°C (63.5°F).

What is the average humidity in December in Sydney?

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

How many days does it rain in December in Sydney?

In December, the rain falls for 11.5 days. Throughout December, 77.6mm (3.06") of precipitation is accumulated.

What is the sea water temperature in December in Sydney?

In Sydney, in December, the average water temperature is 21.9°C (71.4°F). For most, swimming in 21.9°C (71.4°F) is not an enjoyable activity. Furthermore, controlling your breathing becomes progressively more difficult as the water temperature decreases from 21°C (69.8°F) to 15°C (59°F).

When are the longest days in Sydney?

The month with the longest days in Sydney, Australia, is December, with an average of 14.4h of daylight.

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

The average length of the day in December 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, Australia, is 7.9h.

What are the months with the highest UV index in Sydney?

Months with the highest UV index are January and December, with an average maximum UV index of 12.

How high is the UV index in December in Sydney?

In Sydney, Australia, the average daily maximum UV index in December is 12. A UV Index value of 11, and more, symbolizes an extreme health vulnerability from unprotected exposure to the UV radiation.
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 least 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 least 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 the shortest days is June (Average daylight: 9.9h).

  • Average sunshine in December: 7.9h

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