Stinger outlook

Cairns northern beaches to Port Douglas. Days with a higher than usual chance of Irukandji stings, read from the wind forecast.

Reading the wind forecast.

The beaches the outlook covers, sized by the days with recorded stings from 1998 to 2016. The wind is read at the arrow offshore, near Green Island. Choose a day above to colour the map for it.

Higher than usual, 2014 study rule. The wind along the coast the day before is calm or from the north-west: the south-east trade wind has dropped away. Recorded stings on these beaches have mostly come on days like this. This rule, from the published study, colours the map.

Higher than usual, same-day rule (trial). The same test on the day's own wind. BioGeo is testing it: it fitted past sting records slightly better, but not by enough to be sure. How the two compare.

Usual for the season. Irukandji can be in the water on any day of the stinger season. This never means a beach is safe.

Every day of the stinger season

The season runs from November to May. Whatever the outlook says:

From the Queensland Government and Surf Life Saving Queensland.

Past seasons

Play a season through day by day, drag the slider, or choose a day on the charts. The map shows the wind along the coast that day and lights up a beach on a day it had a recorded sting; choose a beach for its own history. Below the map, one chart for each rule shows the days it marked.

Loading past seasons.

2014 study rule

Same-day rule (trial)

How it works

A CSIRO study in 2014 found that Irukandji stings on this coast tend to follow a drop in the south-east trade wind. This page applies a rule drawn from that study to the latest forecast: a day is higher than usual when the average wind along the coast the day before is calm or from the north-west.

The rule was tested on the public records of stings on these beaches before this page was built:

35 of 56sting days, November to March 1998-99 to 2016-17, fell on days the rule marked. It marked about one day in five.
11 of 15sting days caught in the five seasons after the 2014 study's own data ended.
8 in 10of these wind drops are caught by the forecast three days ahead, and about 6 in 10 a week ahead.
Left: the average wind along the shore falls from about 3 metres a second from the south-east a week before a sting to near zero the day before. Right: the rule marked 22% of days, which held 63% of sting days in all seasons and 73% in the seasons after the 2014 study.
The test in one chart. Open it full size to read it on a phone.

Two rules: the one from the study, and one on trial

The outlook shows each day under two rules, one row each. The 2014 study rule is drawn from the published research: it judges a day on the wind along the coast the day before, and it colours the map. BioGeo also tested other versions on the same sting records, and one fitted them slightly better: the same test on the wind on the day itself. That is the same-day rule (trial).

From 1998-99 to 2016-17 both rules marked 22% of days. The 2014 study rule marked 35 of the 56 sting days and the same-day rule 39. The difference rests on 10 sting days that only one rule marked, 7 for the same-day rule and 3 for the 2014 study rule, which is too few to be sure the same-day rule is better. It also has to look one day further into the forecast for each day, which makes it a little less reliable further ahead. We will compare the two as new sting records come in.

Two grids side by side, one row per season from 1998-99 to 2025-26: on the left the days the 2014 study rule marked, on the right the days the same-day rule marked, with each recorded sting as a solid dot where that rule marked the day and an open ring where it did not. 1998-99 to 2016-17: 35 of 56 sting days marked by the 2014 study rule and 39 by the same-day rule, each marking 22% of days.
Every season, the two rules side by side. Open it full size to read it on a phone.

What it cannot do

Most of the sting records come from news reports, so they are few and miss many stings. Calm days also bring more people into the water, and the records cannot tell that apart from more jellyfish. The outlook covers the mainland beaches from Cairns to Port Douglas, not the islands or the reef. It was tested on November to March, and the forecast further out is more likely to change.

This is an experimental outlook from public data, made by BioGeo. It is not a warning service, it can be wrong, and it never means a beach is safe.

Sources