How will El Nino affect your state?

The impact of an El Nino on Australia's rainfall varies greatly from state to state and from El Nino to El Nino.

The Bureau of Meteorology predicts this latest El Nino, the first in the Pacific since March 2010, is likely to be a moderate-to-strong event.

Large areas of inland Queensland, NSW and Victoria, and southern South Australia are already in drought, with rainfall deficiencies stretching back more than two years, BOM climatologist Lynette Bettio says.

"Looking at the Murray-Darling basin, we're starting to see this attrition of below-average rainfall year after year since it was filled again from the 2010-2011 La Nina event," she said.

"We're starting to see that slowly go down. We're starting to see that get down to the level of the 2010 Millennium Drought period."

Climatologist David Jones says typically, NSW, Queensland and Victoria, and particularly northern Victoria - would expect below average rainfall for up to the next two seasons.

"It certainly presents a challenge for farmers," he said.

The Northern Territory could get a delayed monsoon season.

"It will be a pretty unpleasant lead-up to the monsoon season in northern Australia," Dr Jones said.

Southeast and eastern SA tend to follow NSW in El Nino years, Dr Jones said, but the typically western SA and most of Western Australia feels little or no effect on rainfall.

The exception in WA is in Perth and the southwest, which can experience drought during El Nino, while some areas, such as the Goldfields, score above-average rain.

The impact on Tasmania is not as great, Dr Jones said, but Tasmanians can expect drier-than-average weather.