Rain has come to the aid of firefighters battling blazes that started overnight.
Lightning strikes started at least five bushfires in the far west, mostly around Tibooburra, where up to 900 hectares was burnt out.
But Rural Fire Service spokesman Brendan Doyle says the fire that cause the most concern was near the railway line in Ivanhoe.
"We had a few last night around Ivanhoe. One fairly close to the town, only five or six kilometres out of the town - all started by lightning," he said.
"Luckily in that part of the world we had a fair bit of rain involved as well so there was a lot of them rained out before anything happened.
"It's going to be very hot today so we'll keep an eye out on what happens."
Temperatures are expected to reach the mid-40s in some parts of the far west today and tomorrow.
Mr Doyle says it's possible that last night's lightning could ignite fires in the extreme heat later in the week.
"Having that amount of lightning that we had around yesterday in the area there'll be the odd tree that's been struck by lightning and still smouldering so I've got no doubt that over the next two or three days with temperatures in the 40s there will be a few fires that pop up from the lightning activity yesterday," he said.
© ABC 2012
11:27 EST Darwin sweltered through its second hottest September day on record yesterday, with another stinker on the cards again today.