Australia’s long spell of hot and dry weather that has increased the risk of bushfires is set to continue into summer, with the Bureau of Meteorology warning communities should prepare for more severe fire danger.

The BoM’s summer outlook shows a higher than usual chance of above-average day and nighttime temperatures for most of the country, and an above-average chance of drier than average conditions for large parts of eastern Australia.

The bureau said spring, which brought catastrophic fire danger to the east coast, was likely to have been one of the driest on record.

Andrew Watkins, the BoM’s head of long-range forecasts, said there was an 80% chance of warmer than usual days and nights for much of the country through summer.

The outlook is similar for rainfall, with coastal areas of Western Australia from the midwest to the Kimberley the only locations showing increased odds of wetter-than-average conditions.

“Summer’s looking particularly dry with high odds of drier-than-average conditions right down the east coast, including Tasmania,” Watkins said.

A positive Indian Ocean dipole, which moves weather systems that would typically bring rain away from Australia, and a negative southern annular mode, are driving the continued hot and dry conditions.

The onset of the northern monsoon is expected in mid-summer, which Watkins said could increase the odds of closer to average rainfall from January and February.

But he said communities should be preparing for severe weather risks and a continuation of severe fire danger over the coming months.

“We’ve already seen significant bushfire activity during spring, and the outlook for drier and warmer-than-average conditions will maintain that heightened risk over the coming months,” Watkins said.

The outlook for heatwaves is also heightened.

Australia recorded its hottest summer on record in 2018-19. The recent spring bushfires caused six deaths and destroyed more than 600 homes.

The BoM said this spring is likely to have been the fifth driest for NSW and one of its 10th warmest overall.

The trend was the same in almost all other states and territories, with the exception of western Tasmania, where weather conditions were cooler and wetter than usual.

Victoria recorded record-breaking heat in November in many locations but its mean minimum temperatures for spring are on track to be the lowest since 2003.

Meanwhile, firefighters in New South Wales on Thursday were battling more than 150 blazes and issued a warning for residents to prepare for fires to worsen over the weekend.

While there were no total fire bans in place for Thursday, the greater Hunter, greater Sydney, Illawarra-Shoalhaven, southern ranges, central ranges and northern slopes were under “very high” fire danger rating, as was the ACT.

“With more than 150 fires burning across #NSW and the forecast of more hot and windy weather for the weekend please use this time to prepare. Review your bush fire plan, prepare your properties and discuss as a household what you will do if threatened by fire,” the NSW Rural Fire Service tweeted.

On Thursday morning, 64 of the 157 fires across NSW were uncontained.

The Bureau of Meteorology said lightning strikes from thunderstorms which hit Sydney and the state’s north-east on Tuesday had sparked fresh blazes, with an estimated 100 new fires igniting in a 24-hour period.