A key indicator for the strength of El Niño has reached a record high adding to signs that a weather pattern known for causing extreme droughts, storms and floods could become one of the strongest ever. El Niño, the “little boy”, is driven by warm surface water in the eastern Pacific Ocean and its strength is measured by how much higher temperatures are over three-month averages.

In the week ending 16 November, temperatures in the Niño 3.4 region, the central band of affected ocean running either side of the equator from 5S-5N and 170-120W, were 3C (5.4F) above average.

This image obtained November 16, 2015 from the National Oceanic and Atmospheric Administration (NOAA) shows the satellite sea surface temperature departure for the month of October 2015.