SEVERE fire danger is being forecast for NSW later this week as another wave of extreme weather hits much of the state.
The Bureau of Meteorology (BoM) predicts temperatures in many parts of the state will again soar into the 40s on Thursday and Friday.
The extreme weather will be created by a high pressure system fanned by hot northerly winds.
A BoM forecaster said temperatures would climb on Thursday and will be hottest in the state's west, with towns like Moree and Wagga Wagga tipped to hit at least 40C.
He said the mercury would reach the high 30s in western Sydney at places like Penrith and Richmond.
The hottest day over the coming week will be Friday, with Bourke and Tibooburra in the state's west predicted to hit around 42C.
The forecaster said western Sydney would also hit the 42C mark on Friday, but a sea breeze will keep the CBD cooler at around 37C.
He said the hot and windy conditions would ramp up fire danger across the state on Thursday and Friday.
"We're expecting a return to some pretty severe fire danger," the BoM spokesman said.
"We'll probably see some more fire weather warnings and total fire bans."
He predicted a big drop in the temperature on Friday evening as a cool change pushes the mercury in Sydney down to about 26C.