Sydney workers told to 'head home early'

Heather McNab

Transport authorities are urging people in Sydney to leave work early and avoid non-essential travel because the road and rail network may be affected by extreme heat and strong winds.

More than 70 fires are raging across the state with 40 uncontained and more than 10 subject to emergency warnings.

The Greater Sydney, Greater Hunter and Illawarra-Shoalhaven regions have been issued catastrophic fire danger ratings.

"High winds are predicted to sweep into Sydney and the Illawarra this afternoon which on top of the significant heat may start to affect the public transport network," Transport for NSW said in a statement on Tuesday afternoon.

"Most trains will be operating under speed restrictions due to the high heat, as a safety precaution. Strong winds may further affect the road and rail network.

"We encourage you to leave work early if you can due to today's extreme heat and a southerly change predicted for the Illawarra from 5pm and inner-city Sydney just before 6pm."

Transport for NSW also encouraged people to avoid "all non-essential travel on roads and public transport".

Many roads outside of Sydney remain closed due to bushfires.

"If you need to travel, be prepared for conditions to change quickly and roads to close suddenly," Transport for NSW said.

"Also make sure you've got water, food, supplies and a full tank of fuel. Make sure your mobile phone is fully charged before you set out.

"If you're already travelling when a bushfire starts, follow the directions of emergency services personnel."