Environment Canada
www.ec.gc.ca
Ontario Weather Review
December 2013
Bitter cold, an ice storm and snow are on Ontarians’ minds when looking back at
December 2013.
It was colder than normal across the province, but the real story lies in the unrelenting cold
in Northern Ontario. The mean temperatures this month were colder than normal by as
much as 7.2 degrees Celsius! Records were set for the mean temperatures in December
in Sioux Lookout, Dryden, Kenora and Thunder Bay. Another indication of the brutal cold
was reflected in the number of days with minimum temperatures below -30.0 C. According
to the 1971-2000 figures for December, Sioux Lookout normally has 4.6 days on which the
minimum temperature dips below -30C, while Dryden has 3.3 days, Kenora 2.4 and
Thunder Bay 1.5. This December, those locations saw 11, 7, 7, and 9 days, respectively.
In Thunder Bay, a record was set for the extreme minimum temperature for any day in
December at -39.8C on December 31. The former extreme minimum temperature for that
location in December was -37.8C, established on December 13, 1976.
Meanwhile, precipitation was within average amounts for most of the province. Locations in
the northwest, the eastern shores of Lake Superior, Wiarton and parts of southwestern
Ontario did receive above-normal amounts. Given the frigid temperatures, it was no
surprise that the rainfall amounts were lower than normal and the snowfall amounts were
above normal. Muskoka set a new maximum snowfall amount this month with a total of 212
centimetres. Many locations received 1.5 to 1.8 times the snowfall amount expected for
December.
Severe Weather
Early December was marked by a moisture-laden autumn storm which crossed Lake
Superior during the night of December 4-5. Regions to the north and west of Lake Superior
received 10 to 20 centimetres of snow, while northeastern Ontario received between 3 to 9
hours of freezing rain or drizzle.
The period from December 6-12 was a particularly snowy one for locales near and east of
Georgian Bay as a persistent westerly wind set the stage for a multi-day snow squall event.
Twice during this period, a particular squall extended as far inland as the Ottawa area and
eastern Ontario, where snow squalls are seldom observed. While the most persistent
squalls did not directly affect Environment Canada’s monitoring stations, snow
accumulations upwards of 40 centimetres in the affected area were widespread.
Coldwater, Haliburton and Sandfield (Manitoulin Island) reported 60.2, 54.6 and 60
centimetres of snow, respectively, that were associated with this multi-day event. Muskoka
reported the highest snow accumulation for the week with a whopping 128 centimetres of
fresh snow.
During the weekend leading to Christmas (December 20-22), southern Ontario was hit by
two significant storm systems from Texas. This left a large swath of southern Ontario in the
dark, as 20-30 millimetres of ice accumulated on trees, roads and outdoors surfaces. This
significant amount of ice resulted in widespread power outages, trees and tree limbs down
and very icy roads. The areas receiving the biggest impact ranged from north of London
through Kitchener into the Golden Horseshoe, then east along the north shore of Lake
Ontario, and up the St. Lawrence to Cornwall. It took until the end of the month for some
customers to have their power restored. This event was one of the most significant ice
storms in recent years in terms of the size of the area impacted and the number of
customers left without power. Parts of southern Ontario north of this area received a
mixture of snow, ice pellets and freezing rain, with snow and ice pellets’ accumulation in
the range of 10 to 15 centimetres with each system. Ottawa airport reported the highest
snowfall amount (18 centimetres) with this multi-day event. For extreme southwestern
Ontario and regions just north of Lake Erie, rainfall warnings were issued (rainfall warnings
are issued in winter when 25 millimetres of rain are expected in 24 hours). The rainfall
amounts reported ranged mainly from 40 to 50 millimetres, with the highest amount over
the three days being 72 millimetres at the Port Colborne observation site.
Record low mean temperature readings (in °C), ranked by variation from normal:
Location
Sioux Lookout
Dryden
Kenora
Thunder Bay
Mean Temp
-22.2
-21.4
-20.5
-18.0
Normal
-15.0
-14.5
-14.1
-11.6
Difference
-7.2
-6.9
-6.4
-6.4
Previous Record
-22.2 (1976) (tied)
-20.8 (1976)
-20.0 (1976)
-17.9 (1989)
Unusual mean temperature readings (in °C), ranked by variation from normal:
Location
Red Lake
Geraldton
Pickle Lake
Chapleau
Timmins
Kapuskasing
Wawa
Sault Ste. Marie
Sudbury
Mean
Temp
-22.4
-20.6
-23.3
-17.0
-18.4
-19.3
-15.3
-11.0
-13.8
Normal
-16.2
-14.8
-17.9
-11.8
-13.2
-14.3
-10.3
-6.3
-9.5
Difference
-6.2
-5.8
-5.4
-5.2
-5.2
-5.0
-5.0
-4.7
-4.3
Coldest since
1989
2000
1989
1989
1989
1989
1989
1989
2000
North Bay
Earlton
Moosonee
Muskoka
Kingston
Wiarton
Ottawa
Toronto City
-13.1
-16.0
-20.0
-9.4
-5.9
-5.9
-9.6
-2.9
-9.1
-12.1
-16.3
-6.6
-3.2
-3.3
-7.1
-0.9
-4.0
-3.9
-3.7
-2.8
-2.7
-2.6
-2.5
-2.0
2000
1989
1989
2000
2000
2000
2000
2000
Record high snowfall readings (in cm), ranked by variation from normal:
Location
Muskoka
Snowfall
Normal
Difference
Previous Record
212.0
87.6
124.4
211.0 (2008)
Unusual snowfall readings (in cm), ranked by variation from normal:
Location
Ottawa
Thunder Bay
Windsor
Sioux Lookout
Kenora
Snowfall
88.4
73.4
54.2
52.4
46.0
Normal
57.2
44.1
30.1
32.8
27.4
Media: For more information, please contact:
Geoff Coulson
Warning Preparedness Meteorologist
Environment Canada
416-739-4466
(Également offert en français)
Difference
31.2
29.3
24.1
19.6
18.6
Most snow since
2012
1992
2008
2005
2004