The ban was declared on Sunday but has been extended into Monday as the heatwave conditions continue. Port Stephens was expected to reach a top of 38 degrees on Monday.

While cooler than the scorching temperatures experienced on Sunday, where Williamtown RAAF Base hit a maximum of 43.7 degrees, just below its all-time record of 44.8 on January 18, 2013, the dry and windy conditions has the RFS and NSW Fire and Rescue on high alert.

Raymond Terrace Fire and Rescue are urging residents to stay cool and to phone triple-0 at the first sign of a fire.

It comes after a crew from the station were called to a house fire in Raymond Terrace on Sunday afternoon when it was 46 degrees.

NSWFR fire fighters from Raymond Terrace and Tarro responded to reports of smoke coming from a house in Links Drive about 1.56pm.

A Raymond Terrace RFS crew and police also attended.

Fire fighters arrived at the house about 2.05pm and quickly extinguished the fire, which is understood to have started in the bathroom.

The fire, which was contained to the bathroom, was put out by 2.17pm.

No one was home at the time.

The bush fire danger rating for the Hunter on Monday was at severe. More information on fire danger ratings and total fire bans here.

The rating, issued during the bush fire danger period, gives people an indication of the consequences of a fire, if one was to start. The higher the fire danger, the more dangerous the conditions.

Due to the severe fire danger right across the Hunter region, a total fire ban has been put in place. No fires are to be lit during the ban period.

The RFS is urging residents to review their fire plan in the event their home or property is threatened by a fire.