Sydney's driest start to the year in half a century shows little sign of ending but the lack of rain may have an upside for hay fever sufferers.

Paultry rainfall of 7.8 millimetres in August followed 11.2 millimetres in July, making it the smallest tally for those two months in 23 years, Brett Dutschke, a senior meteorologist with Weatherzone said.

That compares with an average rainfall of 176.7 millimetres for those two months. So far this year, Sydney has collected 511 millimetres, or just over half the normal level of rain, making it the driest January-August since 1968, he said.

Two rain-bearing systems may bring some relief to parched regions of the state, including Sydney, next week. Moist easterly winds, more typical of spring, followed by a cold front with a wintry edge could bring falls of as much as 20 millimetres to the city, according to Bureau of Meteorology forecasts.

A taste of spring should certainly be in the air on Saturday, the official start of spring, with a top of 21 degrees predicted - or a couple of degrees above the September daytime average.