The weather bureau says the La Nina pattern affecting Australia is the strongest since 1917.

It started in the middle of last year and has contributed to the warmest oceans on record around Australia.

Floods have drenched wide areas in recent months, wrecking properties, cutting off roads and filling rivers and dams.

Darren Ray from the weather bureau says the strong La Nina pattern has produced more wind and rain.

"There's an argument there that these record warmest ocean temperatures have at least contributed to increasing the intensity of both the flooding and the tropical cyclone activity that we're seeing in the last few months," he said.

"You do tend to see a greater frequency of tropical cyclones so Tropical Cyclone Yasi was a good example."

The current weather cycle is expected to end in the next two months and the forecast beyond is for a wetter-than-normal winter and a drier-than-normal spring.