Sydney train chaos blamed on rain and sickies

More than 150 Sydney train services have been cancelled and authorities are blaming wet weather and a slew of sickies.

150 train services were cancelled on Monday. Source: AAP

Wet weather and a slew of sickies are being blamed for lengthy train delays across Sydney.

Commuters on Monday awoke to the cancellation of several services across the Sydney rail network, with transport authorities blaming "an operational issue".

"Service changes this morning may affect you, due to wet weather and a larger than expected number of staff off sick," Sydney Trains tweeted on Monday morning.

The delays are affecting services on the T1 North Shore, T2 Inner West and Leppington, T3 Bankstown, T5 Cumberland and T8 Airport South lines, with buses called in to assist passengers.

"Trains continue to run on those lines but you may encounter some delays so give yourself some additional travel time," Transport Management Centre spokesman Dave Wright told ABC Radio.