Southeastern Australia will experience a large temperature contrast on Monday, with snow falling in Tasmania while parts of New South Wales reach 35°C amid Extreme fire danger.

A cold front crossing southeastern Australia on Monday will cause cold southwesterly winds originating from the Southern Ocean to clash with much warmer air over the Australian continent. This weather pattern is typical in spring and often causes a stark contrast of summer-like heat and wintery cold weather. On Monday, maximum temperatures will range by around 30°C between Tasmania and NSW.

Cold winds and snow in Tasmania

The cold front passed over Tasmania on Sunday night, delivering a burst of blustery winds and cold air. Wind gusts ahead of this front reached above 100 km/h on Sunday afternoon, including:

137 km/h at Scotts Peak Dam

128 km/h at Mount Wellington

104 km/h at Hobart Airport

Temperatures will only reach about 5–15°C across most of Tasmania on Monday under the influence of cold southwesterly winds behind the front. However, it will feel much colder than this in some areas due to wind chill.

In Hobart, the temperature at 7:10am on Monday was 7°C, but west-southwesterly winds gusting to 39 km/h made it feel more like 0.5°C in the city, due to the combined effect of cold air and wind.

These icy winds are also bringing snow, with Mount Wellington receiving a dusting during Sunday night and snow forecast to reach around 400 m above sea level in the state’s west and south on Monday.

Cool south to southwesterly winds will also affect Victoria and parts of NSW, SA and the ACT on Monday, although these won’t be as strong or cold as the winds buffeting Tasmania.

Hot with elevated fire danger in NSW

While cool air spreads over southeastern Australia on Monday, much warmer air will affect northern and parts of eastern Australia.

In NSW, a stream of warm northwesterly winds will develop ahead of the approaching cold front, causing temperatures and fire danger ratings to rise in some areas.

Image: Forecast maximum temperature on Monday, September 21, 2026. Source: Weatherzone.

Maximum temperatures should reach around 30°C in Western Sydney and 35–36°C in parts of central and northern NSW. Cessnock, Muswellbrook and Singleton are all forecast to reach 35°C on Monday.

This heat will contribute to Extreme fire danger in the Greater Hunter fire weather district, while high fire danger is also likely in other areas of northern and eastern NSW, including Sydney.

Further north, Brisbane is forecast to reach 31°C on Monday, which is around 5°C above average for this time of year. Parts of western and northern Qld are tipped to reach 36 to 37°C on Monday afternoon.

A cool southerly change moving up the NSW coast will reach Sydney late on Monday morning before continuing north and arriving in Brisbane on Tuesday morning.