The fluctuating weather of an Australian autumn is showing its extremes.

As a frontal system ushers Antarctic air into Western Australia giving Perth the coldest April day since 1939, a breeze from the hot interior has just given Adelaide a spell of late summer weather with daily temperatures above 30 degrees Celsius since Tuesday.

That active front caused some wind damage in Perth. Trees and power lines were brought down as the system hit the coast on Thursday night, bringing gusts of 90 kilometres an hour. About 10,000 properties lost electricity.

Surfers no doubt enjoyed the following monster swell with Cape Naturaliste and Albany recording wave heights of up to five metres early on Friday. Inland weather reflected the origin of this cold air: snowfall on Bluff Knoll in the Stirling Ranges.

A flurry was recorded on the peak, the highest point in the Stirling Ranges, on Friday. Australia’s Bureau of Meteorology forecaster Matt Boterhoven said snow was an extremely rare occurrence in April.

“It’s exceptional. We’ve only recorded once, in the last 100 years, snow as early as this on top of the Stirling Ranges,” he said.

Also on Friday, and in vivid contrast, hot air from the interior ahead of this slow-moving cold front brought the hottest day, this late in the season, to Adelaide in 133 years of records with 34C recorded on both Tuesday and Friday. The last hot day of the run, Saturday, registered 32C. April’s average daytime high for Adelaide is 22C and the record remains at 37C.

The fire danger has also being elevated throughout south Australia by the persistent hot, dry wind. Given the tinder-dry conditions throughout the state, any thunderstorms and associated lightning, as this front crosses, risks igniting bush fires.

The forecast highest temperature in Adelaide on Sunday, post front, is 20C, accompanied by showers. Melbourne can expect a drop from its warm spell at 30C (9C above average) to 18C by Monday.

