Australian climate zones have moved significantly in the past 15 years, according to the Australian Grains Export Innovation Centre.

AEGIC has used Bureau of Meteorology rainfall data to revise climate maps, moving some rainfall zone boundaries as far as 400 kilometres.

AEGIC agro-meteorologist Dr David Stephens said the analysis showed significant changes.

Rural news in your inbox? Subscribe for the national headlines of the day.

"Over the last 15 years we have seen a major shift in the rainfall amounts and distribution though the year," he said.

"So we have actually seen summer rainfall increasing over most of the country from 10 to 40 per cent.

"Over much of southern Australia, we have had a 10 to 30 per cent decrease in our May to October rainfall, so that has caused a major shift in our rainfall zones that we are measuring."

Australia's seasonal rainfall zones based on historic data. ( AEGIC )

The maps show regions with a Mediterranean climate and winter dominant rainfall contracting in a south-westerly direction.

Summer dominant and neutral rainfall zones expanded south.

Dr Stephens said the changes appeared to be related to barometric pressure, sea surface temperature and altered upper level westerly winds.

"In the mid '70s there was a weakening of the Indian Ocean trough to the west of Perth that appears to be related to a decline in winter rainfall since then," he said.

"In addition sea surface temperatures have warmed in all season which is beneficial for summer rainfall."

AEGIC's analysis shows that climate variability in some parts of the southwest of Western Australia has actually reduced due to the loss of wet years.

Dr Stephens said the climate had settled into a new pattern and Australian farmers should factor this into their practice.

"I think it would be a little bit naive to be basing your management on climate prior to 2000 it is just a different climate," he said.