The Wimmera Development Agency estimates that heavy rain across Wednesday and Thursday is worth "at least" $100 million to the Wimmera.
Nearly 30 millimetres fell on Wednesday night in Horsham, with scattered showers continuing on Thursday.
WDA executive director Chris Sounness said the financial boost would come from an increase in crop and pasture production.
Mr Sounness, a former chief executive at the Birchip Cropping Group, said the rain came at a perfect time.
"Normally the Wimmera region in a good year is worth around $600 million," he said.
"Our estimate is about an extra $100 million on top of that this year.
"For the Wimmera region, rain in early October is about as good as it gets, especially if the crops are well positioned and had a kind winter.
"It could increase yield across the board by 10-15 per cent.
"Our region is going to receive a big boost."
Grain Producers Australia chairman and Rupanyup farmer Andrew Weidemann said he had received up to 50mm at different parts of his property.
"I can't remember the last time we've had good spring rain like we've had," he said.
"Rain at this time of the year is worth double. The economic value of what we just received from this rain, from quality to yield increases, it is well and truly in the millions.
"There's no question that this is something that is going to help everybody coming out of the coronavirus."
The only negative to come out of the downpour is potential damage to hay.
Tarranyurk farmer Marshall Rodda recorded 38mm at his property across Wednesday and Thursday.
"It's perfect timing actually for cropping, but it will discolour a bit of hay," he said.
"It will certainly help all our wheat crops. They're at a good stage right now. Today would have been the Warracknabeal Show, and it's around that time every year that you'd like to have around 25 mm of rain. So it's a very timely matter.
"It might damage a lot of hay, but you cop that."
While some regions copped a downpour, others received less than expected.
Minyip farmer Ryan Milgate recorded 10mm at his property.
"We're a bit like the poor cousins out here," he said.
"Certainly we were hoping for it. I've got wheat that's about to run out of moisture, it's about to hit wilting point, so we were kind of looking forward to getting enough to help there.
"But the lentils look fantastic, barley is looking good, and the wheat still has plenty of potential, but moisture is going to be the limiting factor.
"We're just readjusting our expectations as we go. It's still looking pretty good. Looking at about an average, maybe just above season."
Mr Milgate said he had also recorded 43mm on grazing country between Stawell and Halls Gap.
"Getting it nice and damp in there in October is beautiful," he said.
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