Fifty bushfires and grassfires are burning across NSW, with flames encroaching on two major highways.
The Princes Highway has been closed in both directions between Timbillica, just north of the Victorian border, and the Victorian town of Orbost due to a large blaze.
The Transport Management Centre on Sunday afternoon warned motorists travelling south on the highway were being turned around.
Earlier on Sunday a grassfire briefly shut down part of the Hume Highway at Goulburn.
At 1pm (AEDT) there were 50 blazes across NSW, including eight that were burning uncontained, according to the state's Rural Fire Service (RFS).
Total fire bans are in force across nine NSW regions due to forecasted hot and windy conditions.
The southern and eastern Riverina regions are bracing for extreme fire danger conditions, with temperatures expected to exceed 40 degrees in the afternoon and wind gusts of 55-75 km/h predicted.
RFS spokesman Matt Sun told AAP crews were on stand-by in the danger zones.
"Aircraft are all tasked and ready to go," he said on Sunday morning.
An air crane based at Albury was being flown to Victoria on Sunday afternoon to help firefighters as they battle some of the worst fire conditions in five years.
