An extreme fire warning has been issued for the Mallee and Wimmera districts in Victoria, as wild weather was tipped to batter Melbourne on Sunday.

The Bureau of Meteorology (Bom) on Sunday noted extreme fire danger ratings for the Mallee and the Wimmera and severe fire danger warnings for the northern country and north central regions.

And in NSW, there were warnings of severe fire danger for the southern and eastern Riverina, as locals braced for hot, dry and windy conditions. Residents in affected parts of NSW and Victoria have been urged to activate their bushfire survival plans and total fire bans are in place.

Callum Stuart, a senior forecaster at the Bom, said temperatures were expected to hit the low 40s along the Murray river in Victoria’s far north on Sunday afternoon.

“There is some risk of some dry lightning with some generally unstable conditions moving in from the west,” he said.

“We’ve already seen a couple of lightning strikes, with probable dry lightning, in parts of the Wimmera.”

At 2.30pm on Sunday a watch and act alert was issued for Robinvale, on the south bank of the Murray River in north-western Victoria, in response to a bushfire 7km south-west of the township.

The fire was not yet under control and those nearby were told leaving the area was the safest option.

A cool change was expected to sweep through Victoria from the south-west later in the day, prompting severe weather warnings for much of state, including Melbourne.

The Bom said areas that would probably be affected included Maryborough, Ballarat, Geelong, Melbourne, Morwell and Moe.

Stuart said high winds up to 100km had already been detected at Mount William, in the Grampians, about 250km west of Melbourne.

He said a “sharp” cool change would hit Melbourne about 4pm, bringing strong winds. The front would reach east Gippsland by Sunday night.

Victoria’s Department of Health and Human services also warned of a “moderate risk” of “epidemic thunderstorm asthma” forecast for parts of the state.

The mercury hit 29C about 2.30pm on Melbourne, still below the predicted top of 33C.

At Hopetoun, 400km north-west of Melbourne, temperatures had reached 38C earlier on Sunday, Stuart said.

There are also strong wind warnings in place in NSW on the Coffs coast, Macquarie coast, Illawarra coast, Batemans coast and Eden coast.

Stuart had previously warned the strong winds predicted for Sunday were the type that could “blow away outdoor furniture or cause weaker tree limbs to come down”.

“But it’s looking like a transient event confined to Sunday,” he said. “By late Sunday, it will be off to the east and things will settle down quite nicely.”

The NSW central west, south coast and western Sydney were battered by storms on Saturday.

The State Emergency Services responded to nearly 200 calls for assistance after the wild weather hit after lunchtime on Boxing Day.