Emergency warnings have been issued for two bushfires burning in northern NSW, with the Rural Fire Service telling some residents it's "too late to leave".
The out-of-control blazes at Busbys Flat Road, south of Casino, and Kildare Road at Tenterfield triggered emergency warnings on Tuesday afternoon.
Residents living in the Tenterfield area have been advised to seek shelter as the fire approaches.
RFS spokesman Greg Allan said the fire was currently burning five to 10 kilometres west of Tenterfield which has a population of just over 4000.
"It's burning under very strong westerly winds, it's heading in an easterly direction towards Tenterfield," Mr Allan told reporters in a recorded message.
"The advice for those in the Kildare Road area and West Tenterfield is to shelter in place as the fire approaches."
Earlier, the RFS said firefighters battling the blaze at Busbys Flat Road faced hot and windy conditions as they tried to control the fire burning in the vicinity of Seery Road and Phillip Swamp Road in the Mount Belmore State Forest.
"Residents in the area of Old Tenterfield Rd near Wyan and Wineshanty it is now too late to leave," the emergency warning states.
"Take shelter when the fire arrives and protect yourself from the heat of the fire."
The fire has already burned through 611 hectares.
Mr Allan said conditions were not tipped to ease until later in the week.
"We're probably not going to see any reprieve until tomorrow," he told AAP.
"We've been seeing very strong westerly winds pushing that fire towards the east, still very high temperatures and very low humidity."
Mr Allan said there were currently 35 firefighters on the ground tackling the blaze.
Amid sweltering heat - with temperatures tipped to reach 37C on Tuesday - total fire bans have been enacted in the far north coast, north coast, New England and northern slopes areas, which are experiencing severe fire danger.
People living in the worst-affected areas have been warned to ensure they have an escape plan.
The RFS tweeted: "Make sure you and your family know what you will do if fire threatens. Ask yourself - when will you go, what will you take and where will you go?"
Despite a cooler weather forecast from midweek - with temperatures expected to drop to the mid-20s - continued dry conditions meant fire dangers would not immediately fall away, meteorologist Jonathan How said.
"With no significant rainfall, fire dangers will remain high to very high until at least the end of the week," he said.
Australian Associated Press