A total fire ban has been imposed across western NSW, with the mercury expected to nudge 40 degrees in some parts of the state on Monday.
Forecast hot and windy weather has also resulted in a severe fire danger rating for the southern Riverina, northern Riverina and far western regions.
An extreme rating has been issued for the southwestern district.The Rural Fire Service is warning of northwesterly winds gusting up to 50km/h, creating a dangerous level of fire risk.
Ivanhoe, in the state's central west, is expected to reach 41 degrees, while further south at Deniliquin, a top of 39 is forecast.The Bureau of Meteorology is also predicting 40 degrees at Wentworth and Hay, and 38 at Griffith.
"Winds are expected to turn to the northwest (on Monday) ahead of a cold front approaching the state," forecaster Chris Webb said."With very hot, dry and fairly windy conditions, we can expect severe to extreme fire danger conditions for the southwest of the state."
Hot and humid weather is forecast for the rest of NSW on Monday, with possible thunderstorms late in the day, he said.Newcastle is expected to reach 28, Gosford 27, and 29 for Lismore.
Central Sydney will experience a slightly cooler 25 degrees, with 31 at Richmond and 32 at Penrith.The heat is likely to ease late on Tuesday, with a southerly expected, Mr Webb said.
