A ridge of high pressure brought clear skies and light winds last night to Winnipeg and the northern Red River valley, allowing widespread frost to form early this morning. Temperatures dipped to a low of -1.5C at Winnipeg airport, officially ending the 2010 growing season for the city. Using airport data, this year's growing season was 132 days , 11 days longer than average, and 18 days longer than 2009. This was due to a fairly early start to the growing season this year with the last spring frost recorded on May 9th at the airport.. some 2 weeks ahead of the normal last frost. At Winnipeg airport, the average growing season is about 121 days between an average last spring frost on May 23rd, and a first fall frost on Sept 22nd. Last year, the airport had a 114 day growing season (Jun 7th - Sept 28th), shortened due to a late spring frost in June.
Elsewhere across the Red River valley, most areas north of Highway 3 had frost this morning with overnight lows of 0 to -2C. The southern valley however escaped frost due to cloud cover that spread along the US border. Areas from Morris southward generally stayed above freezing last night.
Increasing cloud cover and moderating temperatures will prevent the threat of frost over the next few days. In fact, long range models are hinting of above normal temperatures moving in for next weekend into the last week of September with temperatures of 20-25C possible. Here's hoping!