Fires in Western Australia's Wheatbelt have torn through grain crops, leaving a damage bill of more than $3.6 million.

Up to 20 fires were sparked by lightning strikes late on Thursday as thunderstorms rolled through the Dalwallinu area.

Dalwallinu Shire chief bushfire control officer Gary Butcher said about 3,000 hectares of cereal crop was lost in the largest blaze.

Some of the fires joined up to become bigger blazes. ( Supplied: Ross Fitzsimons )

But he said there were a number of other smaller fires burning in crops.

"The biggest fire went [for] 8 kilometres and ended up being about 3 kilometres wide once it hit the eastern salt lake system," he said.

"We had multiple strikes ranging from Kalannie, Buntine, Wubin, Pithara and Dalwallinu … we haven't had as many dry lightning strikes ever.

"It was kind of like 'which fire do I go to?', because they were just striking all over the place and they were joining up and becoming bigger fires.

"[It was] a pretty hectic night."

The fires left a trail of destroyed crops in their wake. ( Supplied: Narelle Dodd )

It could have been worse, shire says

After a poor harvest last year, the Dalwallinu region had been enjoying a good season this year.

Harvest began a few weeks ago, and most wheat crops were averaging about 3.5 tonnes per hectare of grain.

Mr Butcher said the fires could have been worse if the conditions were different.

Farmers are counting the cost of the fires in what was previously a good season. ( Supplied: Narelle Dodd )

"The wind was not too bad actually, so it does give you an idea of what would happen on a hot summer's day," he said.

"[It was] a good wake up drill for those who haven't seen fires.

"I've been doing this job for 30 years and we haven't had it where you haven't had immediate rain."

Mr Butcher said the community rallied together to fight the fires.

"It's what we all train for. We had volunteers that were on the fire ground, farming units, our bushfire trucks, people making food, contractors saying, 'where can I take my 50,000 litres of water for you'," he said.

"So [it was] a good community effort."