|7 am temperatures - southern MB|
Sept 14 2012
And although frost was fairly widespread over the RRV this morning, downtown Winnipeg escaped frost with a low of only +5.0C at the Forks. Downtown Winnipeg has a much longer growing season than the airport, due to the urban heat island effect that keeps night time temperatures warmer than areas near and outside the perimeter. The average first fall frost downtown is Oct 5th, while the last spring frost is May 4th giving an average growing season of 159 days downtown, or 38 days longer than the airport (121 days). For most areas of the city, the length of the growing season lies somewhere between downtown and airport values. At my site in Charleswood, a low of +0.1C was recorded with some light frost.