On the morning of Jan. 30, 1951, the temperature in Madison fell to its all-time record low of minus 37 degrees.
It is difficult to put that amazing record low in perspective. Consider that the coldest morning of this winter season was less than a week ago, when the temperature Wednesday dropped to minus 18 — a full 19 degrees warmer than the all-time record.
The only other time a low temperature as cold as minus 30 occurred in Madison was on Jan. 15, 1963 — exactly minus 30 — nearly 60 years ago. Lows of minus 29 occurred on Jan. 7, 1887, and again on Jan. 21, 1888. Forty-three years ago, on Jan. 11 and again on Jan. 16, 1979, Madisonians awoke to a low of minus 28. More recently, we had three straight days of morning lows at minus 27 on Jan. 18, 19 and 20, 1994, and just three years ago this morning we fell to minus 26.
How did this freakishly low record ever occur in the first place? It required a perfectly aligned set of circumstances:
First, fresh snow cover — not hard to come by in January — that allows the air just above the snow to radiate enormous amounts of heat away from the snow surface over the course of the still long nights of late January.
Second, very light winds such as those that routinely accompany the center of surface high pressure systems. Such light winds ensure that warmer air above the surface is not mixed down to the surface.
Third, rapid export of the cold air from more northern latitudes that ensures the air’s temperature does not moderate on its way to Madison.
These ingredients needed to occur in perfect coordination with each other to get down to minus 37. Given the record value, these circumstances occurred with a level of coordination that had never before (or since) occurred in Madison’s 150-year temperature history.
Given the gradual but systematic global warming that is irrefutably occurring at present, perfect conspiracies of these meteorological circumstances — which will still occasionally occur — will henceforth be fighting a headwind they cannot beat. Thus, it is reasonable to suspect that minus 37 degrees will probably be the all-time record forever.
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 firstname.lastname@example.org or email@example.com.