While an Aussie Christmas isn’t quite complete without sunshine and a cold beverage, Santa might not be bringing perfect weather for everyone this year.

If you live in Sydney, Brisbane or Darwin you should pack an umbrella for Christmas lunch, with the Bureau of Meteorology predicting showers.

The most likely cities to host a perfect outdoor Christmas barbecue will be Adelaide, 30, and Melbourne, 26, which both offer plenty of sunshine.

Usually, Australian capital cities have ideal weather for a day of summer celebrations. The long-term averages of the nation’s capitals have temperatures reaching at least 21 – and that includes Hobart.

Surprisingly, the coolest long-term average maximum on Christmas day on the mainland has Sydney a close second to Melbourne, both about 25 degrees.

Darwin and Perth both consistently surpass 30, though Darwin is also likely to have a thunderstorm or two rolling through in the afternoon.

At 30 degrees and cloudy, Perth is forecast to have a slightly cooler-than-usual Christmas this year, which will be some relief. Last year the Western Australian capital had a scorcher, with a high of almost 40.

So how does your Christmas day look?

Sydney

Christmas
This year: high 25, low 21 – with a shower or two
Last year: 20.8 (it was the coldest maximum of December) / 19.3
Long term average: high 25.6, low 18.1

Boxing Day
This year: high 26, low 20 – with a shower or two clearing
Last year: high 24.7, low 16.4

Melbourne

Christmas
This year: high 26, low 13 – becoming mostly sunny
Last year: high 21.9, low 14.7
Long term average: high 25.1, low 13.4

Boxing Day
This year: high 33, low 15
Last year: high 22.4, low 13.5

Brisbane

Christmas
This year: high 30, low 21 – possible shower
Last year: high 31.8, low 19
Long term average: high, 29.4, low 20.8

Boxing Day
This year: high 30m low 21 – possible shower
Last year: high 28.4, low 20.5

Adelaide

Christmas
This year: high 30, low 13 – mostly sunny
Last year: high 25.5, low 14.4
Long term average: high 27.0, low 15.5

Boxing Day
This year: high 35, low 18
Last year: high 27.8, low 12.8

Perth

Christmas
This year: high 30, low 19 – partly cloudy
Last year: high 39.6, low 19
Long term average: high 31.3, low 17.6

Boxing Day
This year: high 28, high 18 – partly cloudy
Last year: high 37.5, low 23

Darwin

Christmas
This year: high 33, low 25 – possible thunderstorm
Last year: high 34.3, low 24.5
Long term average: high 32.4, low 25.1

Boxing Day
This year: high 34, low 25
Last year: high 33.3, low 24.9

Hobart

Christmas
This year: high 23, low 12 – partly cloudy
Last year: high 20.7, low 11.7
Long term average: high 21.0, low 11.2

Boxing Day
This year: high 25, low 14 – partly cloudy
Last year: high 20.2, low 10

Canberra

Christmas
This year: high 27, low 9 – partly cloudy
Last year: high 18.2, low 16.6
Long term average: high 27.3, low 12.4

Boxing Day
This year: high 31, low 11 – partly cloudy
Last year: high 22.4, low 11.9