Is weather becoming more extreme?
Extreme weather conditions are becoming more common in some parts of the world. Global climate change is influencing the frequency and intensity of extreme weather events.
Ocean currents
El Niño and La Niña are complex weather patterns resulting from variations in ocean temperatures in the east-central equatorial Pacific Ocean, between 120° west and 180° (the International Date Line).
El Niño and La Niña are opposite phases of the ENSO (El Niño-Southern Oscillation) cycle - a term describing the fluctuations in temperature between the ocean and atmosphere in this part of the planet.
El Niño means 'the little boy' in Spanish, and is often referred to as the warm phase of the ENSO - being represented by periods of unusually warm water in the Pacific Ocean around the month of December.
La Niña translates as 'the little girl' in Spanish, and can be referred to as the cold phase of the ENSO. It creates below average temperatures in the east-central Pacific.
El Niño and La Niña episodes usually occur approximately every two to seven years, and last for between nine and twelve months (although can sometimes go on for years). The frequency of their appearance is unpredictable, but El Niño conditions occur more often than La Niña.
The presence of El Niño and La Niña conditions can have a significant influence on weather patterns across a large part of the globe, including changes to rainfall patterns (often leading to flooding) and wind patterns (alterations to the trade winds), as well as making changes to sea temperatures.