Tuesday, February 06, 2007
Currently in Winnipeg, it's -27C... or is it?
Well turn on the radio or look on the web, and you'll find that the current temperature in Winnipeg is -27C as of 1 pm. However, a look at weather stations in and around the city tell a different story. Most stations in the city are around -22C with even some -19C readings around St Vital. (see Google map of Winnipeg area temperatures) So why the big difference from the "official" temperature? That's because the official temperature is taken from the Winnipeg airport weather station, which is located in a remote field in the northwest part of the city. Most times of the year, or if it's windy, there's not a big difference between the airport temperature and the rest of the city. However under clear and cold conditions with a light northwest flow, the airport site is usually several degrees colder than the city itself since it's getting cold air drainage from surrounding snow covered fields. In the city itself however, that light northwest flow is modified by buildings, trees, pavement, etc. so that temperatures can be several degrees warmer than at the airport.. sometimes as much as 5 to 10 degrees warmer. This is known as the "urban heat island effect". This effect will become even more noticeable over the next few weeks as the sun gets stronger and warms up the city core even more. So cheer up.. it's not really -27C, it's a balmy -22C instead! (unless you're standing in a field on the northwest side of the airport!)
Posted by rob at 1:34 PM