Meteorologists in Australia are warning that El Niño, the irregular weather phenomenon caused by fluctuations in the temperature of oceans, is set to be "substantial" - potentially leading to weather chaos around the world in 2015.
In April climate experts in the US announced El Niño had arrived but was "weak". However, the Australian Bureau of Meteorology now believes it could strengthen from September onwards.
"This will be quite a substantial El Niño event," said David Jones from the Bureau. "This isn't a weak one, or a near miss as we saw last year.
"You know, there's always a little bit of doubt when it comes to intensity forecasts, but across the models as a whole we'd suggest that this will be quite a substantial El Niño event."
El Niño is a naturally occurring phenomenon which arrives every two to seven years. The last substantial El Niño was five years ago, leading to drought in Australia, blizzards and flooding in the US, and a freezing winter in the UK.
El Niño is predicted using a network of buoys spread across the tropical Pacific ocean. Data recorded by the buoys, including temperature, wind and currents, is then fed into computers in an attempt to predict its severity. However there are many variables meaning it is still very hard to provide an accurate prediction.
If the predictions are right, Australia will again suffer major drought and parts of the US could be hit by serious flooding. Here in the UK meteorologists predict a cold, wet summer and a freezing cold winter.
Weather Channel meteorologist Leon Brown said: "We will have a cooler summer than normal. We are not expecting any long spells of hot weather.
"The Jet Stream will be a bit further south than normal. That tends to bring wetter weather to Britain.
"El Niño might give us cooler weather. You will struggle to have a hotter summer with El Niño and the Jet Stream being where it is."