THIS autumn is going to get a whole lot wetter - according to Hally and his onion.

May's unseasonable rainfall was no surprise to onion weather man Hallwyn Herrmann who predicted a wet autumn as early as five months ago.

He warns southeast Queensland is yet to experience the worst of the May rain.

"There's more to come in May, it's only early in the month," the 78-year-old from Lowood said.

Hally forecast 'some rain' for the month of May, a bold prediction for a normally much drier month.

That was on New Years Eve 2017 when he used a 100-year-old German tradition to predict the follow year's rainfall using an onion and some salt.

"You peel the onion and cut it in half. Half falls to the left and the other half to the right. The left side is first and you take off six rings which are for January to June, then the other half goes from July to December," he said.

"Then you put your salt in the ring and leave it until 4.30 the next morning. It makes water from the salt and you just measure by eye - you guess how much is in there and the more water there is, the more rain for that month."

Hally Herrmann predicts the weather with onions.
WATCH OUT: Hallwyn Herrmann, 78, predicts more rain this autumn. He uses an onion and salt to forecast weather up to a year in advance. Picture: Rob Williams

Hally said an ordinary brown or white onion would do but it needed to be a decent size and from a local farm.

Hally has been conducting the experiment for 60 years and his weather predictions have always been spot on.

"The readings are pretty good, I can't be exactly accurate every time and I can't predict exactly where it's going to rain but it works for the local area," he said.

"I predicted the 2011 floods and I knew there would be a lot of rain this month."

Hally the weather man: How to use an onion to predict rain.
Hally the weather man: How to use an onion to predict rain.

Hally's 2018 onion cutting weather prediction

January - some good rain

February - rain

March - heavy rain

April - some rain

May - some rain

June - fairly dry

July - some rain

August - some rain

September - rain

October - heavy rain

November - rain

December - good rain