The Bureau of Meteorology says an unseasonal heatwave hitting western and north-western New South Wales could demolish October heat records and place large swathes of the state at bushfire risk.

While Sydney’s top temperature was expected to reach a mild 23C on Sunday, Bourke and Brewarrina braced for their first 40C day since March.

Wilcannia, Cobar and Dubbo were also set to exceed 37C while dust was forecast for most parts west of Griffith and Bourke.

The BoM warned the fire danger rating in almost every NSW/ACT region was high or very high for Sunday, prompted by heat, high winds and low humidity.

By early afternoon, no bushfires were rated higher than “advice” alert level.

Meteorologist Jake Phillips said the bureau was particularly concerned by conditions to the west of the Great Dividing Range. “It’s quite unusual to see temperatures this warm,” Phillips said.

“In large areas of the state we’re seeing daytime temperatures between 8C and 12C above average for this time of the year, and in some places more.

“As we move into tomorrow, it’s quite likely we will see some places getting pretty close to or maybe breaking October records, the most likely areas being the northern tablelands and north-west slopes.”

Very high fire danger was forecast in ACT and 10 NSW regions: greater Hunter, central ranges, southern ranges, Monaro alpine, lower central west plains, upper central west plains, far western, New England, northern slopes and north western. On Sunday afternoon none were yet subject to total fire bans.

All other regions except eastern Riverina had a high fire danger rating.

Phillips said conditions would deteriorate on Monday, making the declaration of fire weather warnings likely for the northern NSW inland. But cooler winds would reduce the fire risk on Tuesday.

“Past that, it’s looking like conditions will be considerably cooler – that’ll bring the fire danger down noticeably,” Phillips said. “Tomorrow is the main day of concern.”

Since 1 July, more than 4,000 bush and grass fires have ignited and 44 homes have been destroyed across NSW.

The BoM said Queensland was also set to scorch through another heatwave this week, with hot, dry and windy conditions increasing fire danger, particularly in the south-east.

BoM forecaster Kimba Wong said temperatures around the state were set to soar 10C to 12C above the average.

“In Brisbane 36C is the current forecast for Tuesday, and that will be the warmest October day since 2005 if it comes up,” she said.

“The maximum temperature record for October in Ipswich is 41.3C, so getting up to 40C, 41C in Ipswich on Monday and Tuesday is certainly getting pretty close.”

Severe fire weather warnings were issued for the Darling Downs and Granite Belt, Maranoa and Warrego regions on Monday, stretching to the south-east, Wide Bay and Burnett on Tuesday.

Wong said conditions would be worse than in early September, when places like the Scenic Rim and Sunshine Coast experienced large bushfires, but they wouldn’t last as long, with a cool southerly change moving up the coast on Wednesday.

“There is the chance of a couple of thunderstorms through the south-east on Monday and Tuesday,” Wong said.

“We aren’t expecting very much rainfall, if any, to come out of those storms though, so they actually do just pose the extra challenge of the potential of dry lightning strikes starting new fires.”

Monday is the Queen’s Birthday public holiday in Queensland, with public pools, beaches and air-conditioned shopping centres expected to be full of those looking to beat the heat.



