EL NIÑO / FIELD GUIDE
El Niño vs. La Niña: What Changes?
El Niño and La Niña are the warm and cool phases of ENSO. Both involve changes in tropical Pacific waters and the atmosphere. Their global impacts are not exact opposites everywhere.
Ocean temperatures: warm and cool
El Niño brings warmer-than-average surface waters to the central and eastern equatorial Pacific; La Niña brings cooler-than-average waters. These are departures from a climate baseline, not absolute temperatures.
Trade winds: weaker and stronger
Trade winds generally weaken during El Niño and strengthen during La Niña. Changes in wind affect warm-water distribution, upwelling and sea surface temperatures.
Neutral does not mean uneventful
ENSO-neutral means the coupled conditions for El Niño or La Niña are absent. Extreme weather can still occur, as other climate drivers remain active.
References
This article explains established climate science using official sources. Consult the references for background, and always check the publication date of any forecast.
NOAA Climate.gov: background referenceNOAA CPC: ENSO Diagnostic Discussion