Over 2,000 people have been evacuated from the Hawkesbury campus of University of Western Sydney (UWS) in the suburb of Richmond as an out-of-control bushfire threatens homes in the area, local media reported on Tuesday.

The fire, covering 60 hectares on Tickner Road in the suburb of Castlereagh in Sydney's far north west, is moving towards properties on Devlin Road, prompting the NSW Rural Fire Service ( RFS) to evacuate homes, according to the Australian Associated Press (AAP).

Firefighters are on the scene in Castlereagh, where the fire has already destroyed one shed. Water-bombing helicopters have been called in to assist firefighters.

A spokesman for the university said the evacuation of the UWS Hawkesbury campus was prompted by a fire-related power outage.

The campus was cleared early in the afternoon, according to a female employee of UWS.

"We're surrounded by fires," she told Australia's Fairfax Radio.

She estimated about 2,500 people had been evacuated.

Firefighters are battling 40 uncontained bushfires burning across New South Wales.

An RFS spokeswoman said windy conditions were hampering firefighters' efforts.

"It is a very high fire danger for the greater Sydney region and obviously the winds are not helping the situation," she told Fairfax Radio.

Emergency warnings have been issued for four bushfires at Windsor, Castlereagh, Winmalee, and Marsden Park in Sydney's west, as the blazes are being fanned by strong northerly winds, with temperatures in Sydney above 30 degrees.