News Release

Ontario Weather Review

January 2011

Unlike January 2010, with its scarcity of snow, most Ontario locations experienced generally normal temperatures and precipitation during January 2011. 

On the first day of the year, single-day maximum temperature records were broken in both Southern and Northern Ontario. The low-pressure system that brought unseasonably warm temperatures did not, however, set any trends for the month. Overall, monthly mean temperatures ranged from normal to slightly below normal temperatures.

In terms of both snowfall and precipitation, most locations received near-normal amounts. Kenora received more snowfall than what would normally be expected in January. A few other locations, mostly in Southern Ontario, received significantly less precipitation than normal.

Severe Weather

The biggest weather story of the month concerned the bitter temperatures felt over a number of days across Ontario. This cold was tied to a slow-moving arctic area of high pressure that was the main weather-maker for the province from January 20-24. Northern and Northwestern Ontario shivered under temperatures that bottomed out between -35 and -45 degrees Celsius. Portions of Northern Ontario experienced biting wind chills on January 20-21 as cold air flooded in and combined with brisk north winds. Although Southern Ontario didn’t experience the same intense cold, minimum temperatures were still well below seasonal values, with readings between -20 and -30 degrees Celsius. In addition, brisk winds in parts of Southern Ontario during the depths of the cold snap also generated some very cold wind-chill values.

Aside from the cold, there were a few notable storm systems that moved through Ontario during the month.

On January 11-12, a low-pressure system moved up from the American Southwest through the lower Great Lakes, bringing a widespread snowfall to Southern Ontario. Many locations received approximately 10 centimetres, with some regions around the west end of Lake Ontario and through the Niagara Peninsula receiving up to 25 centimetres as winds off the lake enhanced the snow totals.

On January 17, snowfall warnings were issued for areas to the north of Lake Superior as a low-pressure system moved over the lake from the American Midwest. Snowfall accumulations between 10 and 20 centimetres were reported due to this system.

And on January 23-24, another system moved into western Lake Superior from the Prairies, resulting in snow for much of Northwestern and Northern Ontario. The two-day accumulations were in the range of 10 to 15 centimetres.

Unusual temperature readings (in degrees), ranked by variation from normal:

Location	Mean Temp	Normal	Difference from normal	Coldest since
Wiarton	-9.2	-6.8	-2..4	2009
Kingston	-9.1	-7.1	-2.0	2009
Thunder Bay	-16.8	-14.8	-2.0	2009

 

 Unusual snowfall readings (in centimetres), ranked by variation from normal:

Location	Snowfall	Normal	Difference from normal	Most snow since
Kenora	53.2	28.0	25.2	2004

 

Unusual precipitation readings (in millimetres), ranked by variation from normal:

Location	Precipitation	Normal	Difference from normal	Driest since
Kingston	20.0	87.6	-67.6	2009 (tied)
Muskoka	47.2	98.5	-51.3	2010
Ottawa	30.2	70.2	-40.0	2004
Sault Ste. Marie	35.4	71.3	-35.9	2010
Peterborough	28.0	58.5	-30.5	1981

Media: For more information, please contact:

Laurie Thibeault
Communications Advisor
Environment Canada – Ontario
905-336-4711