Sydney is having its first wetter than average month since last June, helping the city recover after its driest start to a year in more than a decade.

Like much of NSW, Sydney has experienced an extended run of drier than usual weather since the middle of 2017. For the state's capital city, this included its driest calendar month on record last September, when only 0.2mm of rain reached the gauge at Observatory Hill.

As of 9am on Thursday, the city had collected 143mm if rain so far this month, which is 10mm above the long-term average for all of June.

Prior to this month, Sydney had only received 316mm of rain so far this year. This just over half of the January to May average of 596mm and made this the city's driest start to a year since 2006.

June's welcome rain has lifted the year-to-date ranking, with the city's running rain total now sitting above 2014 up to this point in the year.

Sydney wettest June on record was 642.7mm in 1960 and the driest was 4.1mm in 1962 and 1904.