After a summer-like week in the southwest with maxima running above 30 degrees each day the heat will go on holidays over the coming days, although not for long.

Southwestern WA has seen well above average temperature for this time of the year during this week. Perth has registered tops exceeding 30 degrees since Monday, with heat intensifying during the last few days, leading the mercury to peak above 37 degrees on Friday and Saturday.  

Other towns further south along the west coast also felt like summer was still on. In Bunbury, maximum temperatures exceeded 32 degrees for four consecutive days between Thursday and Sunday. This hot airmass even reached the southern coast, which is unusual for this time of the year. Albany Airport saw its hottest day on Friday (top of 37 degrees) since December 2019.

Image: Forecast maximum temperature on Sunday, based on ACCESS model.

Interestingly, the very broad high over the Tasman Sea that has been sending moist winds over the eastern NSW leading to flooding rain, has also directed a hot airmass over the other side of the country due to persistent easterly winds. Combined with these dry winds, a heat trough has lingered along the west coast preventing any sea breeze from bringing cooling during the afternoons.  

Given that the equinox was on Saturday, day and night have now roughly the same duration. Therefore, unlike the summer peak, minimum temperatures were cool enough to relieve any heat stress accumulated during the day, resulting in only low-intensity heatwave for parts of the southwest.  

Image: Forecast maximum temperature on Tuesday, based on ACCESS model.

A front crossing further south will bring much cooler conditions from Monday, which will make the mercury trend below average from Tuesday to the end of the working week. However, summer seems to be back during next weekend, when we could see tops above 30 degrees again.