Winter 2017-18 Summary
Today, February 28, is the last day of what we call "meteorological winter". Here in Chicago, the 90 coldest days of the year fall between January 1 and March 1, and thus, for clarity and consistency, meteorologists and climate scientists define "winter" as the three months December, January, and February.
So, let's recap! Winter 2017-18 in Chicago was a wild one! There were 4 days where the thermometer went above 60º and there were 9 days when it dipped below 0º! That's quite a range. The average temperature was 26.6ºF which was a mere 0.2ºF above the climatological "normal" of 26.4ºF. But, to call this winter "average" would be a mistake. Two prolonged cold spells (December 24-January 6 and February 5-12) were punctuated by warmer periods (including the end of February which has seen temperatures crest above 60 three times!). December and January saw below-average snowfall, but February brought us 9 days in a row of measurable snow, amounting to 18.3"! Finally, this winter was a whopping 3.5ºF colder than last winter!
These climate observations line up well with the forecast issued for this winter season in mid-November. The forecast was for slightly below average temps (we came in close to normal, but that was driven by some very warm weather in late February), and above-average precipitation/snowfall. For a seasonal forecast, I think that NOAA/the models did very well!
Here are two graphs recapping the winter: