Sydneysiders are about to enjoy the warmest November week in nearly 50 years, with temperatures to reach or exceed 25 degrees over the next seven days.

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.

Jumping for joy: Sydneysiders will be able to enjoy the warmest November week in nearly 50 years. Credit:Ben Rushton

"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.