As farmers on the eastern coast of Australia battle through the worst drought in a century, their Western Australia counterparts are on track to record the best harvest in a decade.

Grain farmers in Western Australia could contribute $6billion to the economy thanks to a combination of rain and high demand.

The increased demand for grain has seen WA prices inflate to as much as $360 a tonne, the most since a record-breaking year in 2016.

Adversely, NSW grain production has slowed to a crawl, as farmers suffer through the worst drought in a century.

It has been at least ten years since pricing seasonal and pricing factors have worked in farmers' favour agriculture marketing director Richard Vincent told The West Australian.

He says that some farmers in the right conditions could end up with as much as 70 per cent higher income than projected.

The eastern states' drought also contributed to their profits, as a lack of production from the east means more demand for the west's produce.

'Although nobody wants to see our eastern states counterparts in drought, the high grain prices are providing enormous opportunities in the west,' Mr Vincent said.

If Western Australian farmers are able to match their export of 16.6 million tonnes, which they're on track to do, their gross income would be about $6billion.

There's also been 30 per cent more rainfall than anticipated in the west, contributing to a 25 to 40 per cent increase in prices for wheat and barley.

Western Australia produces about seven million tonnes of wheat every year.

Some Western Australian farmers reported they had 78mm of rain in the past week.

In the past month, NSW farmers reported less than 10mm of rain, with the trend of low rainfall projected for at least the next three months.

Authorities officially declared the entire state in drought on Wednesday.

With the weather bureau warning there is no end in sight, the Red Cross has set up a relief appeal, while the Salvation Army is distributing food hampers.