Series: El Niño In Wisconsin

The climatic cycle known as the El Niño Southern Oscillation, or ENSO, exerts a powerful but irregular influence on weather around the world. Climatologists predicted that 2015 could be a record year for El Niño, given surface water temperature warming in the eastern equatorial Pacific Ocean — one of the key indicators of the cycle. Its impact in Wisconsin is indirect but causes general warmer conditions in winter — while other parts of the world can see droughts, floods, and massive food insecurity. But El Niño can still cause challenges for Wisconsin farmers, tourism, logging, and wildlife. The cycle is highly unpredictable, and scientists are still trying to understand how it interacts with global climate change.
El Niño forecast
Predictions about the El Niño Southern Oscillation (ENSO) cycle and the complexity of the phenomenon itself can easily create confusion about its impacts on weather and the economy in the U.S. and around the world.
Lake Mendota
Whether looking forward to ice fishing season, crossing fingers for a rare journey to Lake Superior's sea caves on the shores of Bayfield County or just enduring the long cold months of winter, chances are the dates that lakes freeze and thaw are one mark by which one can measure the season in Wisconsin.
Winter tundra along ice age trail
Much of Wisconsin is experiencing a very warm autumn so far, with temperatures higher than average in both September and October. One factor that might be influencing these balmy conditions is El Niño, a recurring global weather pattern that can result in warmer winters for Wisconsin.
ENSO cycle map
The weather phenomenon most commonly called El Niño is one part in a cycle of irregularly changing trade winds and sea surface temperatures in the equatorial Pacific Ocean.
ENSO impact in North America
While the ENSO cycle is unpredictable, climatologists have identified consistent weather patterns during strong El Niño and La Niña years since the 1950s.
ENSO 2015 forecast
The current El Niño is on track to be one of the strongest recorded. Indicators of a strong cycle have been increasingly documented over much of 2015 and continued to mount into autumn.
Ice skaters in Madison
Each El Niño event has a different effect on weather conditions on both global and local scales. These differences in large part depend on how a given El Niño develops.
ENSO in 1997 and 1998
The 1997-98 El Niño event stands out both for its intensity and how it brought the ENSO phenomenon to public attention.
ENSO sea level comparison, 1997 and 2015
The El Niño of 1997-98 was historic, but no two ENSO events are alike, nor are their weather effects in any given location, thanks to differences in how Pacific Ocean waters warm.
ENSO in 2014
The El Niño Southern Oscillation is an irregular cycle in which changing temperatures of surface waters in the tropical Pacific Ocean can result in major impacts on global weather patterns.