What's The "Windchill?"
You hear it all the time. It's 20 below, but the wind makes it feel likes it's -35.
How do they arrive at that figure? Here's a look:
On a normal day when you feel a breeze, your skin registers a cooler feeling. And in the summer, that can be pleasant. Your body automatically works to try and insulate you from whatever the temperature is by warming up a thin layer of your skin, sometimes called the "boundary layer".
But a strong wind blows that away, leaving your skin exposed to the real conditions. Your system will try to build it back up, but the colder it is and the breezier it is, the more the effect is lost and the more your skin temperature drops. And that makes you feel colder.
And there are other factors - your height (tall and thin people become colder faster than those with short and heavy body types), your age (one reason why the elderly often feel cold when you don't) and of course, the kind of jacket and clothing you're wearing.
Environment Canada claims a lot is also based on perception. It says sunshine on a cold day can actually make you feel 10 degrees warmer, even if it doesn't raise the temperature.
In 2001, the federal forecaster helped launch a new way of calculating the wind chill, by using all those factors and measuring how the temperature feels on your face - the one area of your body most often exposed to winter. The result of that perceived difference between the actual temperature and the way it seems is what the wind chill is based on.
So is this Thursday frostiest day in a long time? Not really.
The coldest wind chill recorded in the city of Toronto over the last 30 years was a mind (and finger and toes) numbing -44. It happened on Jan. 4, 1981, when the temperature fell to -29.1 and the wind was gusting at 30 kilometres an hour.
But that's nothing compared to the all time record wind chill recorded in Canada over the past three decades.
Not surprisingly it came in Iqaluit in what's now called Nunuvat, on February 16, 1979. The temperature was -40.9 The wind was blowing at 61 kilometres an hour. And the wind chill that day for anyone crazy enough to be outside there? An unimaginable -66 degrees below zero.
To see a wind chill chart that determines how cold it feels, click here.
Source: Environment Canada
