What a ‘Super El Nino’ means for Minnesota

In August, the National Weather Service’s Climate Prediction Center predicted a greater than 90% chance of a very strong el Niño event during the Northern Hemisphere fall and winter 2026-27.

In Minnesota, el Niño years generally come with warmer temperatures and less snowfall, with the el Niño during the winter of 2023-24 being the warmest winter recorded in the state, shattering high temperature records across the fall, winter and spring.

In the announcement, the Climate Prediction Center also wrote that there’s a high probability that this el Niño might also break records. “During the October-December 2026 season, there is a 69% chance of a historic event that would exceed the strength of previous El Niño events dating back to 1950.”

Quite literally hot on the heels of the warmest Minnesota winter on record, what does such a strong el Niño system mean here in the land 10,000 lakes?

WHAT IS AN EL NIñO?
Niño–Southern Oscillation (ENSO), often referred to as simply el Niños and la Niñas, are oscillating weather phenomena stemming from the heating and cooling of waters in the equatorial Pacific Ocean. These shifts of a few degrees in regional water temperature can radically change weather patterns across the globe.

“It’s a really important region for the climate system,” said Minnesota State Climate Office Senior Climatologist Kenny Blumenfeld.

El Niños are produced from warmer temperatures in the region. La Niñas stem from cooler. These systems oscillate back and forth every two to seven years and with each lasting roughly nine months to two years.
For Blumenfeld, it is important to note that ENSOs are mostly known through their impacts rather than observed phenomena: “It doesn’t really mean anything. We only know it through its tendencies.”

While water temperatures in the equatorial Pacific are monitored and used to classify the intensity of ENSOs, “there’s always some unpredictability,” with the phenomena. Temperature thresholds don’t neatly equate to weather outcomes.

In Minnesota, El Niño winters tend to be warmer with less snow, and la Niña winters tend to be colder with more snow. Those generalities are not without exception, however. Even in El Niño winters, “All we need is a wind shift,” for polar air to blow down from Canada to give residents a taste of the state’s famous winters, said Blumenfeld.

The Climate Prediction Center concurs, writing about this year’s el Niño, “With an event of this magnitude, the chances of experiencing impacts consistent with el Niño are larger, but they are not guaranteed.”

BY THE NUMBERS
Much of the discussion of what has been dubbed the ‘super el Niño’ has been purely hypothetical – even with the high probability – because conditions in the Pacific Ocean just recently officially became classified as an el Niño.

“We’re at the very beginning,” said Blumenfeld.

But in general, the tendencies of warmer temperatures and less snowfall during strong el Niño Minnesota winters are borne out by the numbers.

According to data collected by the Department of Natural Resources, since the winter of 1950-51, winter temperatures with a strong el Niño are on average five degrees warmer that those without an el Niño.

In that same timeframe, overall precipitation between years with strong el Niños and those without el Niños doesn’t change that radically – only by an average of 0.2 inches – but the amount of snowfall does, meaning during el Niño winters, Minnesota gets more rain.

For example, during winters with strong el Niños, the Twin Cities received an average of 13 inches less snow. Because of the warmer temperatures and increased rain, snow doesn’t tend to stick around during strong el Niños and often comes during larger fronts.

“Snow, when you get it, can come in fairly big bursts,” said Blumenfeld.

Another hallmark of years with strong el Niños in Minnesota is early cold fronts in the fall, what Blumenfeld describes as “Almost like one side of a wave,” before warm temperatures settle over the state.

One classic example of these early cold fronts is the famous 1991 Halloween Blizzard that dropped 28.4 inches of snow on the Twin Cities from Oct. 31 through Nov. 3. The storm broke numerous records across the state including for most single-storm snow total, 24-hour snowfall in any season, most snow on Oct. 31, most snow on Nov. 1, most snow in October, earliest 8-inch snow and earliest autumn below zero low.

Despite that explosive storm, “The rest of the winter was kind of a dud,” said Blumenfeld, which is indicative of the early-cold and then warm-winter pattern of Minnesota winters during strong el Niños.

In the meantime, however, summers before an el Niño system don’t follow a reliable pattern, ranging from dry to wet to stormy, said Blumenfeld. This lack of a pattern is in part because of how early into the ENSO phenomena summers usually occur, with the equatorial Pacific waters still warming during the summer and fall.

So, while the numbers suggest Minnesotans can expect a milder winter with less snowfall, meteorology is rarely an exact science. And for those already mourning a shortened season of ice fishing, snowmobiling and skiing, Blumenfeld has some good news: “People will almost certainly get some taste of winter.”