Warmer-than-average spring forecast for most of Australia

A warmer than average spring has been predicted across most of Australia, with temperatures set to rise and rainfall expected to fall below average in many regions.

According to the Bureau of Meteorology (BOM), spring temperatures across the country will climb in the coming days, with several cities already recording their warmest start to the season in years.

Melbourne and Canberra are expected to have their warmest first day of spring in five years, while Hobart is experiencing its warmest start to spring in 13 years, senior meteorologist Jonathan Howe said.

"As if this switch has been flicked, the sun is shining today and the temperatures are rising," Howe said on the first day of spring. "And that will set the scene for what is expected to be a warmer than average spring for most of the country."

Sydney is forecast to reach at least 20C every day for the next seven days, a first for the city this early in spring since 2013, according to 7NEWS Australia. Temperatures in the city could reach 29C on Saturday, while Brisbane is predicted to reach 32C on Friday, Saturday and Sunday.

A Bureau of Meteorology spokesman said the warmth was arriving "right on cue" for the start of spring, adding that the coming week would be notably warm.

"What's notable is just how warm it will be this week," the spokesman told 7NEWS Australia.

The role of El Nino and high pressure systems

Howe attributed the warm pattern to El Nino, which he said is driving above-average temperatures and combining with warm sea surface temperatures off both the east and west coasts.

He said typical spring cold fronts across Victoria, Tasmania and New South Wales would not occur as usual because of blocking high pressure systems.

"We're just not going to get those typical spring cold fronts across Victoria, Tasmania and New South Wales, due to a lot of what we call blocking high pressure systems," he said.

That pattern is expected to bring drier than usual conditions to the east coast and the southwest. However, central Australia could see more rainfall, particularly as tropical moisture moves in from the Indian Ocean.

Fire risk warning for NSW

The warm and dry conditions come with a warning for New South Wales, where fire danger is expected to increase as the state approaches bushfire season.

The Bureau of Meteorology has reminded people to keep an eye on forecasts as the months progress.

The warm spell could be interrupted later in the week, with cooler conditions possible for Melbourne, Hobart and Adelaide as a cold front moves through on Tuesday.