What does a warm fall portend about winter?

Most of the weather experts we know have rated this fall’s weather as reasonably benign in our region. The past month’s average temperature here in Madison was 1.9 degrees above normal, which rounded out a fall season (September through November) that was 1.13 degrees above normal overall – a measurement that supports this widely held opinion.

NWS climate statistics for Madison and Milwaukee Wisconsin for Autumn 2022

At about 1 mile above sea-level, the areal extent of cold air (minus 5 centigrade, or 23 degrees Fahrenheit) over the entire Northern Hemisphere was the eighth smallest in the last 75 years over the September-November period.

This reflects the fact that the most locations in the Northern Hemisphere were on the warm side of their averages this fall.

When one lists all September-November periods since 1948 from “warmest” (number 1) to “coldest” (number 74) by this measure, one creates what is known as a rank list. The same can be done with the areal extent of the cold air during the winter months (December through February).

In the last 73 cold seasons through February 2022, 38 winters were ranked warmer than their corresponding falls, while 35 were colder.

It is not yet known what circumstances might conspire to change the nature of the cold season so abruptly some years, but it is an interesting question whose answer may bear on the ability to make more accurate seasonal forecasts in the future.

As it stands, it is not really possible to tell if the December-to-February stretch this winter will turn sharply colder after our remarkably warm fall.

Winter Temperature Outlook from NOAA

Steve Ackerman and Jonathan Martin, professors in the UW-Madison department of atmospheric and oceanic sciences, are guests on WHA radio (970 AM) at 11:45 a.m. the last Monday of each month. Send them your questions at stevea@ssec.wisc.edu or jemarti1@wisc.edu.

Category: Climate, Seasons

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