It's been a slow start to grain harvest across New South Wales this year but action has finally begun in the central west.

Grain deliveries started last week at Narromine and farmers to the west of Condobolin and near Tottenham and Bogan Gate have been able to get the header into paddocks this week.

Many crops have been damaged by prolonged waterlogging and flooding but the canola crops that are able to be harvested are reported to be some of the best ever.

Agronomic consultant Steve Todd said there was a farmer near Bogan Gate whose canola seed tested to have 50.2 per cent oil and it's the highest he's heard of.

"I have only heard of one delivery ever that's been at 50 per cent," he said.

"I'm sure there has been more but that's extraordinary really but in our part of the world if a grower gets 43 or 44 per cent they're extremely happy.

"To get a 50 per cent oil content is really quite amazing."

James Thomas farms 1600 hectares of canola, wheat, barley and oats north of Condobolin.

Rain pulled up his operations on Wednesday morning so he'll start harvesting again on Thursday.

"Yeah canola is ready to pick up, we'll have a go at it," he said.

"We're hoping with some hot weather maybe next week we'll get a go at the barley and the wheat is 10 days away."

Mr Thomas said he was quietly confident of the quality of his crops this year.

"I think this year they are actually ripening a bit better rather than dying so hopefully it's a good thing," he said.

Graham McDonald, a sheep and wheat farmer 30 kilometres north west of Condobolin, said he was not ready to get the header out yet.

But like most others, he said harvest this year was very late.

"The harvest is late, we are probably about two weeks off," he said.

Mr McDonald said his crops had been water affected and aren't as good as they should be but he's just hoping for fine weather.

"Warm and dry, not wet, we need to get everything off as quick as we can," he said.