Croppers warn winter harvest is not looking great

"It's not looking great, our yield will be down 50 per cent plus," Mr Large said of his wheat and barley crops.

Export hay is looking even worse.

The West Australian cropper, who also chairs Grain Producers Australia, said it was similar in other parts of his state, which is the nation's biggest producer of winter crops.

"I would suggest the state's going to be 50 per cent down on what we produced last year," he said.

"We were pretty close to 25 million tonne last year - anything over 12 million tonne this year would be a good result."

The national agency for agriculture and resource economics expected winter crop production to drop by a third to 45.2 million tonnes following three consecutive record years.

Mr Large said the forecast is optimistic.

"Do I think we would get an average crop out of Australia this year? No, I wouldn't because the bigger grain growing regions are going to be well short," he said.

A lack of rain is driving the drop in volumes.

"If you had said to me three months ago it's not going to rain in October and very little in September, I would have said what would you like to put on it?"

The WA farmer said while the clouds might not have delivered much rain, the high quality of crops was a silver lining.

In Queensland, where yields were also much lower, some areas had no winter crop at all.

Brendan Taylor from the Western Downs said the best performing crops were those planted early, including barley.

"Large areas in southern inland cropping areas did not plant or had crops fail due to little or no rain," he said.

"This year is probably a third of the size of last year's crop."

Good rain has fallen in southern Queensland but much more is needed.

NSW is one of the nation's biggest winter crop producers.

"We've come off a couple of record years but this year's coming right back to average across the state," Moree grain grower Matthew Madden said.

The northern NSW farmer has wound up his winter crop harvest earlier than ever.

"The north is way below last year - southern NSW is better," Mr Madden said.

On the Yorke Peninsula in South Australia, Mark Schilling said the picture was bright.

"We've had an exceptional year, the season has been really good to us," he told AAP.

"Yorke Peninsula's been pretty good, mid north's okay, you talk to some people they've had good crops, some have had bad crops."

In Victoria, where the headers are still rolling, the results are looking positive.

"We're about 80 per cent done and we're looking at above average yields," western Victorian cropper Craig Henderson said.

Farmers are keeping an eye on the rain forecast for the end of the week, hoping it doesn't wash away the good results.

"Fingers crossed for Friday," Mr Henderson said.

Australian Associated Press