With 10 days to go to solidify the record, Chicago has tied for cloudiest January in history, with 20% of possible sunshine (normal is 40%), with 11 of the first 19 days of 2023 giving us exactly zero sun. The record, set in 1998, is 20 of 31 days without sun, and three recent Januaries (2017, 2020, and 2021) saw no sun on 16 of 31 days.
The cause, though, is reflected in us seeing the second-warmest January since records began in 1871, with every single day having an above-normal temperature.
The culprit? A persistent La Niña system in the south Pacific combined with global warming, as WGN-TV meteorologist Tom Skilling explains:
You know, this is a La Niña winter and we’ve done some in-house work on these. Since 1950, La Nina winters have been very volatile in this area. You move from arctic air masses one week to unseasonably mild air the next. We had that cold blast that hit around Christmas week. Now, we’re in the 22nd consecutive day of above normal temperatures. This already is the second-warmest January on the books here — at least so far it is. You have to go back to 1850 to find a January 1-17 period that’s warmer than what we’ve seen this year.
January is typically our coldest and one of our snowiest months and home to some of our blockbuster historic snowstorms, not the least of which is the benchmark blizzard of 1967 that shut the city down.
In Chicago, the winters of the 1970s were collectively our coldest and snowiest on record — and we have records that go back to 1871 and the Great Chicago Fire.
The coldest temperatures occurred in the 1980s. We had back-to-back 26 below zero temperatures in January 1982. And then we had the all-time coldest three years later in 1985 (that was minus 27 degrees).
If you don’t believe climate change is at work, just look at what’s happened to the character of our winters around here. While the decade of the 1970s was the coldest and snowiest on record, we have warmed precipitously since then.
Last time I looked, our winters are running more than 3 degrees on average warmer than the winters of the ’70s, which is a big change. I don’t know if you remember the 1970s, but those winters were barbaric. We’d have these incredible snowstorms and then they’d be followed by these sieges of subzero weather. We don’t get that anymore.
We still have 38 days of winter left, however, and Sunday could see more normal temperatures plus 25 mm or more of snow. And someday, we might even see the sun again.