Sydney may get its wettest day in more than four months later this week, bringing brief respite to the city's parched parks and gardens.

The Bureau of Meteorology is forecasting the city's record dry spell to run until Friday when it predicts 10-20 millimetres will fall.

A rare sight of late - but one that may be about to return for a day at least. Credit:Dominic Lorrimer

Before that, two mild and partly cloudy days with pleasant top temperatures in the mid-20s should extend the number of consecutive days with less than 2 millimetres of rain to 76 days.

The previous run of such days was 64 days during August and October in 1989, the bureau said.