7 day weather forecast

   Effective as of 4:00 PM Saturday December 25 2021

View the latest severe weather warnings from BOM at http://www.bom.gov.au/wa/warnings/ .

Explanatory notes:

Perth has seen the hottest Christmas Day on record with a maximum temperature of 42.8°C at the official Perth Metro station beating the record of 42.0°C set in 1968. In fact, it was the hottest Christmas Day on record for any Australian capital city and possibly any major city in the world based on maximum temperatures at the official stations.

The previous hottest Christmas Day in an Australian capital city was 42.1°C in Adelaide in 1888, but then Stevenson Screen's weren't widely used yet and so such a record is not directly comparable to modern times.

Tomorrow, there is a chance that it could be even hotter than today. Perth's hottest December day on record was Boxing Day 2007 in which temperatures reached 44.2°C at the official Perth Metro station.

This heat is part of an unusual December heatwave, arguably the worst on record for December. At least 3 consecutive days with maximum temperatures above 40.0°C are expected. Perth's longest December 40+°C spell on record was 3 consecutive days in December 2019. Prior to December 2019, 3 consecutive 40+°C days was underheard of in December. The heatwave is due to a very hot air mass lying over the region with the west trough deepening and lying offshore for several days and an upper level high leading to subsidence heating of the airmass.

Conditions are also extremely bad in terms of bushfires with significant dry easterly winds. The easterlies were particularly strong early today and will be again later tonight and early on boxing day where the strong easterly gradient combined with katabatic effect could lead to gusts in excess of 80 km/h over the hills and foothills. The strong easterly gradient with the west coast trough offshore will keep the sea breeze fairly weak, if it develops tomorrow. A weak sea breeze developed today but it did not deliver much relief.

Earlier onset of and a more significant sea breeze and the upper level anticyclone being displaced by an upper level trough means that maximum temperatures on Monday and Tuesday would likely be slightly lower, but still very hot.

The most likely scenario is for the heatwave to end from next Wednesday as the west coast trough moves inland leading to earlier sea breeze onset and the marine layer advecting over the region.

Saturday December 25:

City:

22-43  Degrees Celsius

Very ho ho hot and sunny.

Chance of any rain:0%

Amount:Nil

Perth Metropolitan Area:

Very ho ho hot and sunny.Winds easterly at 25-40 km/h becoming northeasterly at 20-30 km/h in the morning easing to 10-20 km/h in the afternoon with a south-southwesterly breeze at 15-25 km/h in the late afternoon, becoming east-southeasterly at 20-35 km/h later at night.Gusts in excess of 80 km/h possible over the hills and foothills early and again later at night.

Sunday December 26:

City:

28-44  Degrees Celsius

Very hot and mostly sunny.

Chance of any rain:5%

Amount:Nil

Perth Metropolitan Area:

Very hot and mostly sunny.Winds east-northeastery at 20-35 km/h becoming northeasterly at 20-30 km/h in the morning easing to easterly at 10-20 km/h in the afternoon with a south-southwesterly sea breeze at 10-20 km/h possible near the coast, becoming easterly at 20-5 km/h at night. Gusts in excess of 80 km/h possible over the hills and foothills early, 75 km/h later at night.

Monday December 27:

City:

27-40  Degrees Celsius

Very hot.Partly cloudy.

Chance of any rain:10%

Amount:Nil

Perth Metropolitan Area:

Very hot.Partly cloudy.Winds east-northeasterly at 20-35 km/h easing to 15-25 km/h in the morning tending south-southwestery in the afternoon becoming southeasterly at night.

Tuesday December 28:

City:

25-39  Degrees Celsius

Very hot and mostly sunny.

Chance of any rain:0%

Amount:Nil

Perth Metropolitan Area:

Very hot and mostly sunny.Winds northeasterly at 15-25 km/h tending south-southwesterly at 20-30 km/h in the afternoon and evening becoming south-southeasterly at 10-20 km/h later at night.

Wednesday December 29:

City:

22-37  Degrees Celsius

Hot and sunny.

Chance of any rain:0%

Amount:Nil

Perth Metropolitan Area:

Sunny.Very hot inland.Winds northeasterly at 10-20 km/h shifting south-southwesterly at 15-25 km/h by afternoon.

Thursday December 30:

City:

19-31  Degrees Celsius

Mostly sunny.

Chance of any rain:0%

Amount:Nil

Perth Metropolitan Area:

Mostly sunny.Winds southerly at 10-20 km/h becoming south-southwesterly at 15-25 km/h from afternoon.

Friday December 31:

City:

19-31  Degrees Celsius

Mostly sunny.

Chance of any rain:0%

Amount:Nil

Perth Metropolitan Area:

Mostly sunny.Winds south-southeasterly at 15-25 km/h tending south-southwesterly at 20-35 km/h in the afternoon.

Saturday January 1:

City:

17-30  Degrees Celsius

Mostly sunny.

Chance of any rain:0%

Amount:Nil

Perth Metropolitan Area:

Mostly sunny.Winds east-southeasterly at 15-25 km/h tending south-southwesterly at 20-30 km/h in the afternoon.

Charts: