Late winter and early spring in Chicago have always had some ups and downs in temperature. This year, with a week left to go in meteorological winter, has been nuts.
It got down to -2.8°C just before 8am today. That's not too far from normal—for March 8th. But here are the temperatures over the past 10 days:
Date |
High |
Low |
Avg |
Tue Feb 20 |
18.9°C |
1.1°C |
10.0°C |
Mon Feb 19 |
15.6°C |
2.8°C |
9.2°C |
Sun Feb 18 |
5°C |
-11.1°C |
-3.1°C |
Sat Feb 17 |
1.7°C |
-8.3°C |
-3.3°C |
Fri Feb 16 |
2.8°C |
-6.7°C |
-1.9°C |
Thu Feb 15 |
8.9°C |
3.3°C |
6.1°C |
Wed Feb 14 |
6.7°C |
-4.4°C |
1.2°C |
Tue Feb 13 |
1.7°C |
-13.9°C |
-6.1°C |
Mon Feb 12 |
-2.8°C |
-15.6°C |
-9.2°C |
Sun Feb 11 |
-5.6°C |
-11.7°C |
-8.7°C |
But looked at another way, using the normal temperatures for each day in Chicago, we've been all over the calendar:
Date |
Felt like |
Tue Feb 20 |
May 2 |
Mar 30 |
Apr 17 |
Mon Feb 19 |
Apr 17 |
Apr 9 |
Apr 13 |
Sun Feb 18 |
Mar 2 |
Brrr! |
Feb 11 |
Sat Feb 17 |
Feb 13 |
Feb 4 |
Feb 11 |
Fri Feb 16 |
Feb 19 |
Feb 16 |
Feb 16 |
Thu Feb 15 |
Mar 19 |
Apr 12 |
Apr 6 |
Wed Feb 14 |
Mar 9 |
Feb 26 |
Mar 6 |
Tue Feb 13 |
Feb 13 |
Brrr! |
Brrr! |
Mon Feb 12 |
Brrr! |
Brrr! |
Brrr! |
Sun Feb 11 |
Brrr! |
Brrr! |
Brrr! |
In other words, yesterday's high temperature felt like April 30th; the low felt like March 30th; but the overall temperature of the day felt like May 19th. (Where it says "Brrr!" the temperature was below the normal temperature for any day of the year. In other words, it felt like mid-January on a bad day.) Also: nice going, February 16th! Totally normal day in February.
I should point out, these are the 1981-2010 normals. I'll leave it as an exercise for the reader to recalculate these values using earlier normal sets; 1951-1980 would be particularly interesting, I should think.
It's all part of the fun in a continental climate that has tons more energy, and thus volatility, than it had in centuries past. And thanks to continued anthropogenic climate change, we will continue to have winters that whipsaw between frigid and spring-like for a few decades, until Chicago's climate settles into a subtropical pattern where it rarely freezes. If you remember what Tennessee or North Carolina was like 50 years ago, that's where Chicago is headed 50 years from now.