Does a warm September suggest anything about winter?
This month will go down as one of the warmest Septembers on record. For some places, it will probably take the #1 position outright. Does a warm September mean anything when it comes to what the upcoming winter will be like? Will it also be warm, or will we make up for it with cold and snowy weather?
Let’s look at the ten warmest Septembers, based on the temperature averaged across the entire state. They happened in 1931, 1897, 2015, 1933, 1998, 1939, 1925, 2005, 1978, and 2016. How did their temperatures and precipitation rank in the following December through February? Remember that precipitation is the combination of rainfall and melted snowfall. Snow data can be flaky (pardon the pun), so it’s not available for this specific purpose.
The place rankings are warmest to coolest and wettest to driest. Anything below 49th place for temperature was cooler than normal, and below 59th place for precipitation was drier than normal.
1931: 12th place on temperature, 7th place on precipitation (out of 122 years)
1897: 76th place, 16th place
2015: 8th place, 1st place
1933: 22nd place, 103rd place
1998: 15th place, 79th place
1939: 77th place, 88th place
1925: 35th place, 60th place
2005: 18th place, 92nd place
1978: 121st place, 58th place
2016: 7th place, 24th place
While the majority of the following winters were warmer than normal, it’s not necessarily a guarantee. After all, the ninth-warmest September was followed by the second-coldest winter! When it comes to precipitation, it’s a wash; half were wetter and half were drier.
The moral of the story: the ten warmest Septembers statewide tended to be followed by a milder winter statewide, but there was no trend on precipitation.