Sadly, tornados devastated central Florida this week, including a church designed to resist a category 4 hurricane. The twister that destroyed this building must have been a 3 on the Fujita scale based on my comparison of its wind speeds with that of the Saffir-Simpson categorization for hurricanes.

Scales like this are popular for devasting forces, such as the Richter for earthquakes and decibels for Rolling Stones (a joke). I’d like to contribute one of my own:Cold Force. My cold force (CF) scale begins at 40 degrees C (104 F) and increases by 1 for each decrease of 10 C. For example, today I experienced a temperature of 6 degrees F (-15 C), which translates to a CF over 5 on the Anderson scale. This measure is a useful predictor for the number of layers a person should wear to maintain body temperature. Notice all the clothes I wore today – not quite enough for prolonged exposure – take my word on that!

I experienced extreme heat, over 100 degrees F, last July at a Baltimore Oriole baseball game in their home field — Camden Yards. Since this correlates to 0 CF, one could comfortably go around in literally nothing, but I recommend at least a bathing suit. At 1 CF (30 C, 86 F), you might consider putting on a t-shirt. Next on the scale comes 20 C or 68 F, at which point (CF 2) a nylon windbreaker would be good – in other words a second layer.

Wind-chill becomes a factor below CF 3 (10 C, 50 F). The Mount Washington Observatory, “Home of the world’s worst weather,” provides the mathematical formula below their chart of temperature versus wind. They also provide a calculator for this purpose. According to Environment Canada , residents of Pelly Bay experienced a wind chill of -91 degrees C on January 28, 1989. That created a freezing force of 13 by my reckoning. However, it would be ridiculous to put on that many layers of clothes. Maybe that’s why last winter while vacationing in Miami during unseasonably cold weather – CF 2, a radio DJ derisively noted that anyone wanting to see Canadians need only drive by the beach. I was decked out in my bathing suit and driving there myself at the time!