While temperatures in the mid-to-high 20s are common for the city this time of year, it's unusual for Sydney to have such a prolonged run of uninterrupted warm weather.

"The last time Sydney had seven consecutive days with maximum temperatures equal to, or above, 25 degrees in November was back in 1968, and it's only happened twice in November in the last 118 years," Weatherzone meteorologist Ben Domensino said.

The consistently warm weather is the result of a high pressure system - known as a "blocking high" - that is centred over the Tasman Sea and is stopping any strong cold fronts from moving up Australia's east coast, Mr Domensino said.

Over the past week, Melbourne residents have had sweltering spring temperatures, enduring the longest stretch of November days exceeding 28 degrees on record.

For six days, Hobart has experienced temperatures over 26 degrees, the first time in Tasmania since records began in 1882.

Now, the stagnant pool of warm and humid air that has broken November temperature highs down south is creeping up eastern Australia, as the blocking high starts to travel across to New Zealand.

Further north, though, onshore winds have caused Brisbane cooler than average maximum temperatures almost every day for more than two weeks.

Mr Domensino said that, that unlike its neighbours, Sydney weather is going to be "in the most fortunate position".

"Sydney in this case is being spared from extreme heat. For those who do like the warmer weather, it's going to be fairly nice," he said.

"Though the nights may feel a little warm for some, with Sydney set to average lows of 19-20 degrees this coming week; definitely not cool nights, especially as the air is quite humid."

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