There was flash-flooding on roads in parts of Sydney on Monday morning after heavy showers.

However, despite appearances, the Bureau of Meteorology said the rainfall was moderate and parts of western Sydney did not receive any rain at all.

Pedestrians brave the rain in Sydney's CBD on Monday. Credit:AAP

The weather bureau issued a road weather warning on Monday morning after heavy showers created potentially hazardous driving conditions across the inner city and northern suburbs.

Flash flooding at Capitol Square in Haymarket disrupted light rail, with buses replacing trains between Central and The Star casino before services were restored about 1.30pm.