Gunnedah residents woke up to the distinct smell of smoke Monday morning and there isn't a fire close by.
The smoke has blown in from the east coast's bushfires, and it won't clear up anytime soon.
Tamworth and Region Weather's David Farrenden said east and south easterly winds had pushed the thick smoke inland.
"The whole of the ranges are on fire so anywhere from Sydney to the border [of NSW] there's fires, it doesn't really matter where the winds are going to come from, they're still going to make it inland," Mr Farrenden said.
"There's not a lot in the wind department so it looks like it'll stick around.
"Tomorrow's looking a bit dodgy too so it's going to be smoky again tomorrow."
The smoke has also meant the Air Quality Index is considered poor, at 129. At this level, the Office of Environment and Heritage suggest that those with heart and lung diseases should stay inside and limit outdoor exercise.
This is even higher in Tamworth, at a hazardous level of 357. At this level, everyone is urged to stay inside as much as possible and avoid outdoor exertion.
Mr Farrenden said residents shouldn't panic when seeing smoke, and should keep an eye on the NSW Rural Fire Services' Fires Near Me app in case there were fires nearby in future.
Gunnedah will also face a heatwave this week, with temperatures set to soar to 39 degrees on Saturday.
Tuesday, Wednesday, and Friday will see temperatures of 37, Thursday will hit 38, before beginning to cool down on Sunday at 35 degrees.