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wind chill
DCHP-2 (Jun 2016)
n. & adj. — Outdoors, Science
a measure of subjective coldness.
Type: 4. Culturally Significant — During cold weather, the perceived air temperature, as opposed to its objective temperature, depends largely on wind speed. Humans feel warmer on calm days than windy ones. A wind chill index incorporating this effect was created in the late 1930s based on work by two American explorers, Paul Siple and Charles Passel, who coined the term in 1939 (Cheung 2009: 21; see Environment Canada reference). Siple and Passel used plastic containers of water to measure the time required for water to freeze in different conditions during their Antarctic mission in 1945 (Gross 2010: 45).
However, the original system of measurement created confusion and became obsolete. In 2000, Environment Canada held a workshop on wind chill, which led to further research in the field. In 2001, a new wind chill formula was presented in Toronto that models skin temperature under various conditions of wind and temperature in more effective and realistic ways than the older model. Technically speaking, the current wind chill factor is a different index, which marks a change in meaning. Many Canadians would argue, however, that the term is culturally salient in Canada's colder climate (consider also, e.g. Environment Canada's involvement) and of special importance to the country as a whole (as opposed to only some regions in other countries).
The frequency chart shows that the term is predominant in the US, with the numbers being much higher than in other countries. Canadian hits occupy second place, which shows the importance of the term in these two countries (see Chart 1).
However, the original system of measurement created confusion and became obsolete. In 2000, Environment Canada held a workshop on wind chill, which led to further research in the field. In 2001, a new wind chill formula was presented in Toronto that models skin temperature under various conditions of wind and temperature in more effective and realistic ways than the older model. Technically speaking, the current wind chill factor is a different index, which marks a change in meaning. Many Canadians would argue, however, that the term is culturally salient in Canada's colder climate (consider also, e.g. Environment Canada's involvement) and of special importance to the country as a whole (as opposed to only some regions in other countries).
The frequency chart shows that the term is predominant in the US, with the numbers being much higher than in other countries. Canadian hits occupy second place, which shows the importance of the term in these two countries (see Chart 1).
Quotations
1949
Even on milder days (-20°F) with a strong wind, the wind-chill factor prevents sustained periods of work.
1958
The thermometer might read ten below zero but the weather report would point out that due to the "wind chill" it was as cold outside as it would be at forty below zero in still air.
1962
The Calgary Herald obligingly broke out a kind of cold weather discomfort index called a wind chill index. Based on studies at the joint U.S.-Canadian Weather testing station at Churchill, the wind chill index goes on the theory that, just as in summer when it is not the heat but the humidity, in winter it is not the cold but the wind. Thus the wind chill index measures both; a temperature of -30° with little or no wind is not as bad as a temperature of, say, 20° above zero with a 20-m.p.h. wind.
1978
In Southern Ontario, winds gusted at 75 kilometres (45 miles) an hour and created a wind-chill factor of -40 Celsius (-40 Fahrenheit). In the northern areas of Sault Ste. Marie, North Bay and Sundbury, winds reached a high of 90 kmh.
1989
According to an excellent article by Bob Carpenter in the January issue of WildBird, our three most dangerous enemies in winter are wind chill, frostbite, and hypothermia. "If any combination of ambient temperature and airflow speed produce a wind-chill factor of 30 degrees F (minus 1 C) or less," wrote Carpenter, "it's time to make sure you are properly equipped and clothed."
1999
The temperature at night fell to -24, or, with wind chill added, the equivalent of -33. Wind blasted through cracks at the top of the tents. One Quebec Scout described the night as hell.
2015
Local board vice-chair Marty Fairbairn said that didn't sit well with some local parents, who urged greater consistency, noting the closures didn't always match those at the counterpart public board in Waterloo Region. Current guidelines allow Upper Grand staff to close schools for the day if temperatures dip below -35C with the wind chill.
References
- Cheung (2009)
- Gross (2010)
- Environment Canada • "Why a new program in 2001?"
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