December weather forecastPerth, Australia

The central business district of Perth, Australia The central business district of Perth, Australia

December

Weather in December

Closing the year, December in Perth is filled with the arrival of summer, bringing back familiar higher temperatures. To herald the summer, Perth experiences a significant rise in temperature, soaring to 29.1°C (84.4°F), alongside reduced rainfall of 10mm (0.39"). As the sun reaches its zenith, endless sunny days redefine the lifestyle of Perth's inhabitants. The warming temperature coupled with summer festivities make it a popular month for beach visits and water sports. December's weather sets the stage for grandeur New Year's Eve celebrations, bidding adieu to the year on a warm note.

Temperature

December's beginning signals an average high-temperature of a still moderately hot 29.1°C (84.4°F), barely different from November's 26.6°C (79.9°F). Perth undergoes a major shift from daytime highs, averaging an enjoyable 16.4°C (61.5°F) during the night in December.

Heat index

The heat index value for December is appraised at 29°C (84.2°F). Exposure and extended activity could potentially cause a state of fatigue and lead to heat cramps.
Note that heat index values are valued for light wind and location in the shade. When under direct sunshine, the heat index may be elevated by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'feels like' or 'real feel', evaluates the perceived heat by adding the effect of moisture in the air. The effect of weather is individual, with a variety of people experiencing it differently due to distinctions in body mass, height, and level of activity. Remember, direct sunlight exposure can heighten the heat impact and might increase the heat index by 15 Fahrenheit (8 Celsius) degrees. Heat index values are quite important for children. Children usually face more risks than adults as their ability to sweat is less. Additionally, their larger skin surface in relation to their petite bodies and higher heat output due to their activities increases their vulnerability.

Humidity

In December, the average relative humidity is 41%.

Rainfall

In Perth, in December, it is raining for 3.9 days, with typically 10mm (0.39") of accumulated precipitation. Throughout the year, in Perth, there are 108.4 rainfall days, and 725mm (28.54") of precipitation is accumulated.

Sea temperature

In December, the average sea temperature in Perth, Australia, is 20.9°C (69.6°F).
Note: Swimming in water at 20.9°C (69.6°F) is not a pleasing experience for the majority. As the temperature descends from 21°C (69.8°F) to 15°C (59°F), controlling breathing becomes increasingly hard.

Daylight

December has the longest days of the year, with an average of 14h and 12min of daylight.
On the first day of December, sunrise is at 5:03 am and sunset at 7:08 pm. On the last day of the month, sunrise is at 5:13 am and sunset at 7:25 pm AWST.

Sunshine

January and December, with an average of 11.5h 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 in Perth. A UV Index value of 11, and more, symbolizes an extreme health hazard from exposure to the Sun's UV radiation for average individuals.
Note: A typical high UV index of 12 in December suggests the following recommendations:
Take all necessary precautions, as unprotected skin can burn in minutes. Be aware that the sun's UV radiation is strongest between 10 a.m. and 4 p.m. and try to reduce direct sun exposure during this period as much as possible. Always opt for UVA and UVB-resistant sunglasses on radiant days. Sunscreen of at least SPF 30 should be applied generously and reapplied often on overcast days, especially post swim or outdoor exercise.

Frequently asked questions

An average high-temperature, in December, in Perth, is 29.1°C (84.4°F) and the average low-temperature is 16.4°C (61.5°F). In December, the average heat index (a.k.a. 'real feel', 'feels like'), which takes the relative humidity and factors it into the air temperature reading, is appraised at 29°C (84.2°F).

In Perth, Australia, the average relative humidity in December is 41%.

In Perth, Australia, in December, during 3.9 rainfall days, 10mm (0.39") of precipitation is typically accumulated.

In Perth, the average seawater temperature in December is 20.9°C (69.6°F). For swimming, a surface water temperature of 20.9°C (69.6°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).

December has the longest days of the year, with an average of 14h and 12min of daylight.

The average day length in December in Perth is 14h and 12min.

On the first day of December in Perth, Australia, sunrise is at 5:03 am and sunset at 7:08 pm. On the last day of the month, sunrise is at 5:13 am and sunset at 7:25 pm AWST.

January and December, with an average of 11.5h of sunshine, are months with the most sunshine.

In Perth, the average sunshine duration in December is 11.5h.

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

In Perth, the average daily maximum UV index in December is 12. A UV Index value of 11, and more, symbolizes an ultimate hazard to health from exposure to Sun's UV rays.
Average high temperature
Average low temperature
Average humidity
Average rainfall
Average rainfall days
Average sea temperature
Average UV index

Average temperature in December
Perth, Australia

  • Average high temperature in December: 29.1°C

The warmest month (with the highest average high temperature) is February (31.7°C).
The month with the lowest average high temperature is July (18.4°C).

  • Average low temperature in December: 16.4°C

The month with the highest average low temperature is February (18.4°C).
The coldest month (with the lowest average low temperature) is July (7.7°C).

Average humidity in December
Perth, Australia

  • Average humidity in December: 41%

The month with the highest relative humidity is July (57%).
The month with the lowest relative humidity is February (38%).

Average rainfall in December
Perth, Australia

  • Average rainfall in December: 9.9mm

The wettest month (with the highest rainfall) is July (144.7mm).
The driest month (with the least rainfall) is February (8.8mm).

Average rainfall days in December
Perth, Australia

  • Average rainfall days in December: 3.9 days

The month with the highest number of rainy days is July (16.9 days).
The month with the least rainy days is February (2.1 days).

Average sea temperature in December
Perth, Australia

  • Average sea temperature in December: 20.9°C

The best month for swimming (with the highest average sea temperature) is March (23.4°C).
The coldest months (with the lowest average sea temperature) are September and October (19°C).

Average daylight in December /
Average sunshine in December
Perth, Australia

  • Average daylight in December: 14h and 12min

The month with the longest days is December (Average daylight: 14h and 12min).
The month with the shortest days is June (Average daylight: 10h and 6min).

  • Average sunshine in December: 11h and 30min

The months with the most sunshine are January and December (Average sunshine: 11h and 30min).
The month with the least sunshine is June (Average sunshine: 5h and 54min).

Average UV index in December
Perth, Australia

  • Average UV index in December: 12

The months with the highest UV index are January and December (UV index 12).
The months with the lowest UV index are June and July (UV index 3).