Temperatures to soar 'well above normal' in NSW before southerly buster brings relief

This summer is on track to be one of the warmest on record for Australia, and the current heatwave is producing the hottest weather in years for pockets of NSW.

On Wednesday afternoon Smithville right near the SA border climbed to 47.2 degrees, the warmest temperature recorded anywhere in NSW since late 2020.

Coastal regions also saw temperatures spike as a north-westerly airstream carried the hot air east – Merimbula nudged 38 degrees, the towns highest maximum in six years.

A heatwave extends across most of NSW this week as temperatures soar well above normal.

Temperature of 48 degrees possible

While Wednesday saw temperatures as much as 11 degrees above average, for most of NSW the heatwave will peak through Thursday and Friday as the north-westerly winds continue to feed in very hot air from Central Australia where maximums this week have already peaked at 48C.

Today's highs should climb up to around 12 above average for January — the hottest weather in years for many locations:

Again the absolute hottest temperatures will be recorded near the SA border where potentially maximums will reach up to around 48 degrees.

It is the warmest in NSW since Walgett sweated through a 48C day in December 2020.

Sydney will be spared the most oppressive conditions today by cloud cover and possibly onshore winds.

However the temperature will struggle to drop at night and Friday's minimum of around 25C in most suburbs will be the warmest in four years.

Southerly buster to arrive Friday

A cooler southerly change will replace the hot north-westerlies in the far south of NSW tonight before spreading north through the remainder of southern NSW on Friday morning.

The change will then accelerate up the coast through lunchtime and gain strength, comfortably passing southerly buster thresholds by the time it reaches Sydney in the early afternoon.

The city's temperature should rapidly climb to the mid to high thirties through Friday morning, then experience a sudden drop of around 10 degrees in an hour along with gusts for the coast above the buster criteria of 54 km/h.

While southern NSW enjoys relief on Friday, northern regions will continue to roast under the hot air mass and combined with freshening winds, an "extreme" fire danger is predicted for the Hunter.

Several locations across the Hunter and Mid North Coast can expect their warmest day in years on Friday before the southerly arrives later in the afternoon or evening, including:

The cool southerly will then sweep to the NSW far north coast early on Saturday.

However the change will stall over the northern inland, leading to a prolonged spell of hot days close to 40C for areas west of ranges north of about Gunnedah.