Temperatures are set to soar this week.
Temperatures are set to soar this week. Contributed

Heatwave on the way: Get ready for 'unusually hot' temps

YES, it's Summer - but some unusually hot weather is about to hit the Northern Rivers this week.

Tomorrow temperatures will soar to 40C in Casino, but will be peaking on Wednesday with 43C forecast.

It will be 37C in Lismore tomorrow, a significant jump from today's maximum of 33C.

On Wednesday Lismore is set to swelter through a high of 39C.

The Bureau of Meteorology's Three-day Heatwave Forecast starting tomorrow for Tuesday, Wednesday and Thursday predicts a widespread low intensity heatwave for the North Coast.

Bureau of Meteorology forecaster Rebecca Farr said conditions will mostly be hot, dry and windy and advised of keeping an eye on fire risk alerts.

"We're heading for a top of of 33C but tomorrow temperatures are increasing from a dry front that is moving through the south of the state,” Ms Farr said.

"Ahead of the front we have northerly winds that are bringing warm, dry air into the region causing a build in temperature.

"The front isn't expected to reach the east until Wednesday. This front is dry and we're not expecting rainfall over the next couple of days.”

She said they were "very high temperatures for this area” and was generally drier conditions than we have been seeing.

"The Lismore average is 30C so these temperatures are 7-9C above average, so it will feel pretty hot.”

The good news is things will drop right back from Thursday with temperatures in the high 20s to low 30s with cloudy conditions and a chance of showers and a thunderstorm.

There is a slight chance tomorrow afternoon - separate to the front we have a bit of convergence in the winds so there is a chance of seeing a storm or shower briefly tomorrow afternoon.

"After the change has come through late Wednesday evening we could see a brief shower,” Ms Farr said.

"For Thursday we're back to sitting around 30C and on Friday and into the weekend.

"Another high pressure ridge moving over the state could bring a bit more of that south-easterly onshore flow which could bring showers.”