By tossing around a few numbers and making some general assumptions, I developed an efficiency rating that measures “bang for the cold weather buck” when it comes to producing snow. The statistics confirm that when it comes to snow making and cold weather, the Twin Cities is like a souped-up car that struggles to reach 50 mph.
First, some background on my approach. I decided to measure “cold hours” as every hour of temperatures at 32 or below. That’s also the temperature at which legitimate snowmaking becomes a possibility. I divided the number of cold hours by the average annual snowfall (obtained here). This results in a snow-making efficiency factor expressed as cold hours per inch of snow produced.
I developed the numerator by reviewing daily averages for each of the cities detailed below. Here’s how I measured that. For a given day, if a city had an average high of 40 and an average low of 24 (a daily average of 32), I assumed that half the day’s hours were at or below 32. Using the same general assumption, if a city had an average high of 40 and an average low of 28 (a daily average of 34), I determined that 10 of those 24 hours were at or below 32.
I came up with a scale of cold hours per day based on the theory above. If a city’s daily average was 44 or higher, I assumed they had no “cold hours.” If the daily average was 20 or lower, I assumed that had 24 cold hours. It’s not a particularly scientific approach and I’m sure there are inherent statistical biases, but given my limited abilities and the desire to come up with a ballpark estimate, I think it works for the purpose.
The results were generally as I expected and probably won’t surprise most weather enthusiasts, yet I think it’s fun to see an actual number assigned. As you can see from the table, Erie, Pennsylvania must only endure 17.7 cold hours to receive an inch of snow. Rocky Mountain locations also score well in the snow efficiency rating. Aside from cities bordering the Great Lakes, the Midwest must endure the coldest temperatures for relatively little snow. The Twin Cities requires nearly 54 hours of sub-freezing temperatures to receive one inch of snow. For comparison, Burlington, Vermont, has almost as many cold hours as the Twin Cities, but receives 60 percent more snow. East coast cities are more “snow efficient” with cold weather than Midwestern cities, though obviously not as prolific as lake-effect locations.
Hardly surprising data to be sure, but hopefully rather entertaining for weather enthusiasts. The Twin Cities climate may produce one of the better theatre of seasons in the country, but when it comes to snow production, the long-duration winter – which consists of an estimated 2,675 hours of sub-freezing temperatures – is a relative dud.