The irukandji jellyfish may be elusive during far north Queensland's big wet, but they're set to come back in big numbers when the sun comes out, says one expert.
"All this rain, it'll fire all the jellyfish up," says toxicologist Professor Jamie Seymour.
"What you tend to find is after you have big rainfall events, like we're having at the moment, we'll have large number of jellyfish, assuming the weather settles back down. If we don't get rain, we get very small numbers of irukandji."
One of the world's deadliest creatures, the jellyfish prefer calm, warm waters and tend to stay away during heavy rainfall, with some far north areas receiving up to 200mm since Boxing Day.
On the weekend before Christmas Day, two northern Queensland beaches were closed down due to the jellyfish, including Ellis Beach near Cairns after a teenaged girl was hospitalised with stings to her upper body.
Prof Seymour said Queensland had recorded almost 20 irukandji stings this year, including four off Fraser Island.
"It is above average. In Cairns, we've had at least seven stings. This time last year, we had one," he said.
"The season has become longer. 50 years ago , the season was about a month. Now it's about 5-6 months.
"It correlates quite nicely with rising water temperature."