'Strongest' El Nino for decades
Weather experts say that the Earth could be experiencing the strongest El Nino for more than 60 years.
It usually occurs every two to seven years.
It's when the waters of the Pacific Ocean become very warm and this changes weather patterns around the world.
The Met Office - who keep an eye on the world's weather for the UK - says that 2015 has already seen the warmest start to any year on record.
Watch the clip to see BBC reporter Tomasz Schafernaker explain how El Nino has been affecting countries around the world.