Twin Cities ClimateExplorer

Climate patterns

El Niño, La Niña & teleconnections

Every year of the Twin Cities record classified by its ENSO phase and intensity, plus the five large-scale patterns that load the dice for Minnesota seasons.

El Niño, La Niña & neutral years

Each year is labeled by its October–December (OND) ENSO phase, representing the approach to winter — not a whole-year or NOAA-defined ENSO event classification.

1950–2025 uses NOAA CPC ONI version 6 for October–December. 1871–1949 uses estimates of undocumented provenance, marked † and not directly comparable in reliability.

NOAA transitioned to the Relative Oceanic Niño Index (RONI) for operational ENSO monitoring in February 2026. The values shown here are historical Niño 3.4 anomalies on the ONI method, not current RONI values, and the two are not directly interchangeable.

Total years

155

El Niño

56

La Niña

46

Neutral

53

What is ENSO?

The El Niño–Southern Oscillation is a coupled ocean–atmosphere cycle in the tropical Pacific. El Niño tends to favor warmer Upper Midwest winters, while La Niña can favor colder winters; local snowfall outcomes vary greatly. The label here describes October–December conditions, not every month of a year.

Intensity is based only on the October–December three-month ONI anomaly (weak: 0.5–0.9°C; moderate: 1.0–1.4°C; strong: 1.5–1.9°C; very strong: 2.0°C or more). NOAA defines full ENSO episodes using persistence across multiple seasons; this table does not attempt that.

Strong / very strong late-year ONI

2023El Niño· Strong2015El Niño· Very Strong2010La Niña· Strong2007La Niña· Strong1997El Niño· Very Strong1988La Niña· Strong1982El Niño· Very Strong1975La Niña· Strong1973La Niña· Strong1972El Niño· Strong1965El Niño· Strong1955La Niña· Strong1940El Niño· Strong1925El Niño· Strong1918El Niño· Strong1899La Niña· Strong1896El Niño· Strong1888La Niña· Strong1878El Niño· Strong1877El Niño· Very Strong
YearPhaseIntensityOct–Dec ONI (°C)Winter temp signalWinter precip signal
2025La NiñaWeak-0.6VariableNear normal
2024Neutral—-0.3VariableNear normal
2023El NiñoStrong+1.9Much warmerDrier
2022La NiñaWeak-0.8CoolSnowier
2021La NiñaWeak-0.9VariableDry
2020La NiñaModerate-1.1ColderSnowier
2019El NiñoWeak+0.7MildWet
2018El NiñoModerate+1.0MildWet
2017La NiñaWeak-0.6CoolNear normal
2016La NiñaWeak-0.5CoolSnowier
2015El NiñoVery Strong+2.5Much warmerDrier
2014El NiñoWeak+0.7MildNear normal
2013Neutral—-0.1VariableCold
2012Neutral—+0.1Very mildDry
2011La NiñaModerate-1.0ColderSnowier
2010La NiñaStrong-1.6ColderSnowier
2009El NiñoModerate+1.3MildDrier
2008La NiñaWeak-0.6CoolSnowier
2007La NiñaStrong-1.6ColderSnowier
2006El NiñoWeak+0.9MildDrier
2005La NiñaWeak-0.6CoolSnowier
2004El NiñoWeak+0.6MildNear normal
2003Neutral—+0.3Near normalNear normal
2002El NiñoModerate+1.2MildDrier
2001Neutral—-0.3VariableNear normal
2000La NiñaWeak-0.8CoolNear normal
1999La NiñaModerate-1.3ColderSnowier
1998La NiñaModerate-1.3ColderSnowier
1997El NiñoVery Strong+2.3Much warmerDrier
1996Neutral—-0.4CoolNear normal
1995La NiñaModerate-1.0ColderSnowier
1994El NiñoWeak+0.9MildNear normal
1993Neutral—+0.2VariableWet
1992Neutral—-0.2MildNear normal
1991El NiñoModerate+1.2WarmerDrier
1990Neutral—+0.3MildNear normal
1989Neutral—-0.1VariableNear normal
1988La NiñaStrong-1.8ColderSnowier
1987El NiñoModerate+1.2MildDrier
1986El NiñoModerate+1.1WarmerDrier
1985Neutral—-0.3Near normalNear normal
1984La NiñaWeak-0.9CoolNear normal
1983La NiñaModerate-1.0ColderSnowier
1982El NiñoVery Strong+2.0WarmerDrier
1981Neutral—-0.2VariableNear normal
1980Neutral—+0.1Near normalNear normal
1979El NiñoWeak+0.5VariableNear normal
1978Neutral—-0.1VariableNear normal
1977El NiñoWeak+0.8MildNear normal
1976El NiñoWeak+0.8MildNear normal
1975La NiñaStrong-1.5ColderSnowier
1974La NiñaWeak-0.9CoolSnowier
1973La NiñaStrong-1.9ColderSnowier
1972El NiñoStrong+1.8WarmerDrier
1971La NiñaWeak-0.9CoolSnowier
1970La NiñaWeak-0.8ColderSnowier
1969El NiñoWeak+0.8MildNear normal
1968El NiñoWeak+0.7MildNear normal
1967Neutral—-0.4VariableNear normal
1966Neutral—-0.2MildDrier
1965El NiñoStrong+1.8WarmerDrier
1964La NiñaWeak-0.8ColderSnowier
1963El NiñoModerate+1.2MildNear normal
1962Neutral—-0.2VariableNear normal
1961Neutral—-0.1VariableNear normal
1960Neutral—-0.1VariableNear normal
1959Neutral—+0.2VariableNear normal
1958Neutral—+0.4MildDrier
1957El NiñoModerate+1.4WarmerDrier
1956Neutral—-0.4ColderSnowier
1955La NiñaStrong-1.6ColderSnowier
1954Neutral—-0.4CoolSnowier
1953El NiñoWeak+0.5MildNear normal
1952Neutral—-0.1VariableNear normal
1951El NiñoModerate+1.0MildNear normal
1950La NiñaWeak-0.7VariableNear normal
1949El NiñoWeak+0.9†MildNear normal
1948La NiñaWeak-0.7†CoolSnowier
1947La NiñaModerate-1.3†ColderSnowier
1946La NiñaWeak-0.9†CoolSnowier
1945El NiñoModerate+1.1†MildDrier
1944El NiñoWeak+0.8†MildNear normal
1943Neutral—0.0†VariableNear normal
1942La NiñaWeak-0.5†CoolSnowier
1941El NiñoModerate+1.2†MildDrier
1940El NiñoStrong+1.6†WarmerDrier
1939El NiñoModerate+1.0†MildDrier
1938Neutral—0.0†VariableNear normal
1937Neutral—0.0†VariableNear normal
1936Neutral—0.0†VariableNear normal
1935Neutral—0.0†VariableNear normal
1934El NiñoWeak+0.7†MildNear normal
1933Neutral—0.0†VariableNear normal
1932Neutral—0.0†VariableNear normal
1931El NiñoWeak+0.6†MildNear normal
1930Neutral—0.0†VariableNear normal
1929El NiñoWeak+0.9†MildNear normal
1928La NiñaWeak-0.5†CoolSnowier
1927Neutral—0.0†VariableNear normal
1926El NiñoModerate+1.1†MildDrier
1925El NiñoStrong+1.5†WarmerDrier
1924Neutral—0.0†VariableNear normal
1923El NiñoWeak+0.8†MildNear normal
1922La NiñaWeak-0.5†CoolSnowier
1921Neutral—0.0†VariableNear normal
1920Neutral—0.0†VariableNear normal
1919El NiñoModerate+1.1†MildDrier
1918El NiñoStrong+1.5†WarmerDrier
1917La NiñaModerate-1.3†ColderSnowier
1916La NiñaWeak-0.6†CoolSnowier
1915Neutral—0.0†VariableNear normal
1914El NiñoWeak+0.9†MildNear normal
1913Neutral—0.0†VariableNear normal
1912El NiñoWeak+0.6†MildNear normal
1911El NiñoWeak+0.5†MildNear normal
1910El NiñoModerate+1.1†MildDrier
1909Neutral—0.0†VariableNear normal
1908Neutral—0.0†VariableNear normal
1907La NiñaWeak-0.5†CoolSnowier
1906Neutral—0.0†VariableNear normal
1905El NiñoModerate+1.1†MildDrier
1904La NiñaWeak-0.9†CoolSnowier
1903Neutral—0.0†VariableNear normal
1902El NiñoWeak+0.8†MildNear normal
1901Neutral—0.0†VariableNear normal
1900La NiñaModerate-1.0†ColderSnowier
1899La NiñaStrong-1.7†ColderSnowier
1898La NiñaModerate-1.3†ColderSnowier
1897El NiñoModerate+1.0†MildDrier
1896El NiñoStrong+1.6†WarmerDrier
1895El NiñoWeak+0.8†MildNear normal
1894Neutral—0.0†VariableNear normal
1893La NiñaWeak-0.5†CoolSnowier
1892Neutral—0.0†VariableNear normal
1891El NiñoWeak+0.6†MildNear normal
1890Neutral—0.0†VariableNear normal
1889La NiñaModerate-1.3†ColderSnowier
1888La NiñaStrong-1.6†ColderSnowier
1887El NiñoWeak+0.9†MildNear normal
1886Neutral—0.0†VariableNear normal
1885El NiñoWeak+0.7†MildNear normal
1884La NiñaWeak-0.9†CoolSnowier
1883La NiñaModerate-1.4†ColderSnowier
1882La NiñaWeak-0.8†CoolSnowier
1881Neutral—0.0†VariableNear normal
1880El NiñoWeak+0.9†MildNear normal
1879Neutral—0.0†VariableNear normal
1878El NiñoStrong+1.7†WarmerDrier
1877El NiñoVery Strong+2.2†Much warmerDrier
1876El NiñoWeak+0.5†MildNear normal
1875La NiñaWeak-0.8†CoolSnowier
1874Neutral—0.0†VariableNear normal
1873Neutral—0.0†VariableNear normal
1872Neutral—0.0†VariableNear normal
1871Neutral—0.0†VariableNear normal

† Pre-1950 estimate of undocumented provenance. NOAA CPC's Oceanic Niño Index record begins in 1950, and the earlier classifications on this site are not drawn from a named reconstruction dataset, so treat them as approximate.

The patterns behind Minnesota weather

Teleconnections are large-scale, long-distance climate patterns. They don't dictate a single day, but they load the dice for entire seasons. Here are the five that matter most for the Twin Cities.

Data sources & methods

ENSO

El Niño–Southern Oscillation

+positive phase

Upper Midwest signal: Warm phases tilt the Upper Midwest toward warmer, drier winters; cool phases toward colder, snowier ones.

A tropical Pacific ocean–atmosphere cycle, measured by the Niño 3.4 sea-surface temperature anomaly (the ONI method). The most closely watched driver of Minnesota's seasonal winter outlooks.

NAO

North Atlantic Oscillation

+positive phase

Upper Midwest signal: Positive NAO drives a stronger westerly jet → milder, wetter MN winters. Negative NAO opens the door to arctic outbreaks.

A pressure seesaw between the Icelandic Low and Azores High that controls how cold air spills south over the eastern U.S.

AO

Arctic Oscillation

+positive phase

Upper Midwest signal: Positive AO keeps frigid air penned up north. Negative AO lets the polar vortex sag south — bitter cold for Minnesota.

The ring of atmospheric pressure around the Arctic. When it weakens (negative), the jet stream buckles and arctic air floods the Midwest.

PNA

Pacific-North American

+positive phase

Upper Midwest signal: Positive PNA builds a western ridge / eastern trough — colder, stormier MN. Negative PNA flattens that out.

A wave train of pressure anomalies from the North Pacific across North America that shapes the storm track over the Upper Midwest.

PDO

Pacific Decadal Oscillation

+positive phase

Upper Midwest signal: A positive or negative PDO changes the broader North Pacific background and can interact with ENSO, but it does not by itself predict a warm, cold, or snowy Minnesota winter.

A broad North Pacific sea-surface temperature pattern that often persists across years. Its timing and influence are variable, and Minnesota weather is affected by many other factors.

Want the latest available indices?

The newest ENSO, NAO, AO, PNA and PDO values, each labelled with the month it was observed, live on the dashboard.

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Oceanic Niño Index over time

Pink bars = El Niño (≥ +0.5°C), blue bars = La Niña (≤ −0.5°C), grey = neutral.

1950–2025 bars: NOAA CPC ONI v6 for October–December, the approach to each winter. Pre-1950 bars are undocumented estimates, not CPC ONI data.

ENSO phase summary

Average index value and year count by phase across the whole record — values before 1950 are estimates, marked with † in the ENSO table. Years without an index value are left out of the average rather than counted as zero.

El Niño

56years

Avg Niño 3.4: +1.1°C · 56 years

Neutral

53years

Avg Niño 3.4: -0.04°C · 53 years

La Niña

46years

Avg Niño 3.4: -1°C · 46 years

PDO & ENSO — a layered relationship

The Pacific Decadal Oscillation is the slow background state that ENSO rides on top of.

Warm PDO + El Niño

A positive PDO can coincide with El Niño-like North Pacific ocean patterns. This combination may shift winter probabilities, but it cannot guarantee a mild Twin Cities winter and does not establish causation.

Cool PDO + La Niña

A negative PDO can coincide with La Niña-like ocean patterns, but its effects on Minnesota winter temperature, precipitation, and snowfall vary. It is one influence among many.

Warm PDO + La Niña

A positive PDO and La Niña are not necessarily contradictory. Their interaction can change broad climate odds, but the result is not a dependable Minnesota snowfall forecast.

Cool PDO + El Niño

A negative PDO can occur during El Niño. Competing Pacific patterns may alter the jet stream, but they do not reliably cancel one another or dictate winter weather locally.

Think of ENSO as the gas pedal and the PDO as the road surface. The same El Niño or La Niña hits differently depending on the slow PDO background underneath — which is why two El Niños of equal strength can deliver very different Twin Cities winters.

These pairings describe tendencies seen across the record, not a settled outcome: the same combination of phases has produced very different Twin Cities winters.