Monday, December 15, 2008

Wind chill.. Get used to that term..

OK, OK.. so we're all complaining about the cold. And it looks like we'll be stuck with it for awhile (possibly through the end of December) so we might as well get used to it (or leave if you're lucky enough) The main issue over the next week or two will be the wind.. which will determine whether or not windchill warnings are required. Environment Canada issues windchill warnings when the windchill is forecast to reach or exceed -40 for at least 3 hours, with a windspeed of at least 11 km/h. This week, with high temperatures around -25C, and low temperatures in the -30 to -35C range, it won't take much wind to reach those windchill warning levels. At -30, you need a windspeed of only 11 km/h to produce a windchill of -40. At -25C, you need a sustained wind of at least 33 km/h to produce a windchill of -40. These values look likely tonight into Tuesday, but winds may be light enough by Wednesday so that windchill may not be an issue (though it will still be cold) Wind speeds may pick up again in the 15-25 km/h range for the end of the week.

Remember that windchill is not an actual temperature, but rather a measure of the cooling rate of the atmosphere based on the temperature and windspeed. Your body loses heat more quickly when a wind is present.. the faster the wind, the more rapidly you lose heat. For more details on this windchill issue, read my entry from last winter explaining the windchill factor.


  1. Does anyone know what the coldest windchill is for Winnipeg?
    How about Manitoba???
    - 47 windchill tonight into tomorrow morning is gonna HURT!!!

  2. Winnipeg's coldest windchill was recorded on Feb 1 1996.. at 8 am, the temperature was -41C with a 19 km/h wind giving an extreme wind chill of -57.

  3. I remember Feb 1, 1996. Feb 2 was just as cold, maybe without the extreme windchill. However, by Feb 6 we had a thaw and reached the freezing mark. I don't think that will happen this month.

  4. Windchill warning has been dropped for much of southern MB this morning (Tuesday) including Winnipeg as windchill values have risen above the -40 threshold. But it's still darn cold out there with a brisk south wind of 30 km/h and -24C temperatures giving windchills around -38. Wednesday should feel a lot more comfortable as winds will be light (10 km/h or less) It's all about the wind now..