The Rural Fire Service will introduce a total fire ban today after Maitland, Merriwa, Cessnock, Singleton, Mangrove Mountain and Peats Ridge had record highs for November.

Jerry's Plains, Newcastle University, Paterson, Scone, Williamtown and Lake Macquarie topped 40 degrees.

Singleton was the hottest place in the Hunter, reaching a sweltering 45 degrees.

Weatherwatch meteorologist Don White said the heatwave was caused by persistent north-easterly winds driving hot air into the region over recent weeks.

Coastal winds had helped mitigate the effect in Newcastle and other coastal areas, he said.

"Lots of places across the State had record temperatures today," Mr White said. "We're going to have a very hot season."

Strong winds followed the heat into the Hunter last night, with 95 kmh recorded at Norah Head and 102 kmh at Merriwa.

The region was expected to receive relief with a late change tomorrow afternoon, but Mr White said yesterday that temperatures would rise again by Wednesday.

While they avoided the worst of the heat, Newcastle power users experienced at least three power surges from about 11am yesterday.

The momentary outages were attributed to a cable fault near the substation in Tyrrell Street, Newcastle.

EnergyAustralia spokesman Allyn Hamonet said the cable fault had resulted in an hour-long blackout of about 1200 Merewether properties.

Mr Hamonet said power demand had been heavy but the cable fault was unrelated.

The fault was also cited as the cause of the series of smaller power outages in the Newcastle CBD throughout the day.

While the State experienced heavy electricity demand yesterday, cooler afternoon temperatures meant power use did not hit the record levels authorities expected earlier in the day.

NSW, Queensland, South Australia, Tasmania and Victoria run on an interconnected national power grid overseen by the Australian Energy Market Operator.