News Release

Ontario Weather Review

March 2011

March 2011 continued the normal trend from earlier in the year, with normal temperatures and precipitation amounts recorded.

Mean temperatures for most locations throughout the province were near to normal, but on the cooler side. A few locations in Northern Ontario, such as Elliot Lake, Geraldton, and Red Lake, were colder than normal by a few degrees.

Rainfall and snowfall amounts for March were near normal for most of the province, with a few exceptions. In the south, Hamilton, Muskoka, Toronto, Waterloo and Windsor received more rainfall than normal, with amounts ranging from 26 millimetres to 45 millimetres above normal values. Red Lake and Waterloo received roughly 30 centimetres in excess of normal snowfall amounts, more than double the March snowfall amounts for these locations. Conversely, Wawa received less than half the snowfall normally expected for this period.

The trends are similar for total precipitation. Most locations received near normal precipitation amounts, although amounts for Northern and Far Northern Ontario Regions ranged from normal to drier conditions. The opposite was observed in Southern Ontario Region, with precipitation amounts ranging from normal to above normal amounts.

Severe Weather

March was an active month for major storms, and being a seasonal transition month, the storms produced a mix of different types of precipitation. Over southern Ontario, a storm that tracked across the lower Great Lakes brought significant amounts of rain and snow to many areas from March 5 to 7. Rainfall amounts generally ranged from 20 to 35 millimetres, and then once winds shifted to the northwest, temperatures dropped and precipitation fell as snow, with amounts from 5 to 15 centimetres. The automatic monitoring station in Brockville reported 61 mm of total precipitation from this event.

Another storm from March 9 to 11 brought a mix of snow, freezing rain and rain to southern Ontario. Ottawa reported 13.6 centimetres of snow and 37 millimetres of total precipitation. Further southwest, the precipitation began as snow but soon changed to rain, with rain being the predominant precipitation type. Toronto received 10 centimetres of snow and 28 millimetres of rain. Over the extreme southwest, the rain turned back to snow on March 10 as temperatures cooled off, with some areas near London and Sarnia receiving up to 20 centimetres of snow.

A third significant event occurred in the south on March 23, when a low pressure system tracking across the lower Great Lakes provided a snowstorm that dumped 10 to 20 centimetres of snow. The highest amount was 26 centimetres, reported in Waterloo.

Over central Ontario, the first two systems that affected the south provided 15 to 20 centimetres of snow to North Bay and Sudbury on March 4-5, and significant precipitation again on March 9-11, with North Bay receiving a mix of rain, snow and freezing rain, and Sudbury receiving 33 centimetres of snow.

Over the northeast, a storm on March 17 brought a mix of freezing rain and snow to Geraldton and Kapuskasing, with Kapuskasing reporting 22 centimetres of snow.

March was a fairly quiet, inactive month across the northwest. The exception to this occurred in the Thunder Bay area from March 6 to 8, when easterly winds brought lake effect snow to the area. While the airport measured only 23 centimetres, unofficial reports outside of the city suggested that some areas received as much as 40 to 50 centimetres.

Temperature and Precipitation Tables

Unusual mean temperature readings (in °C), ranked by variation from normal:

Location	Mean Temp	Normal	Difference	Coldest since
Elliot Lake	-6.0	-3.2	-2.8	2008
Red Lake	-10.2	-7.7	-2.5	2002
Geraldton	-11.1	-9.0	-2.1	2008

Unusual rainfall readings (in mm), ranked by variation from normal:

Unusual rainfall readings (in mm), ranked by variation from normal:

Location	Rainfall	Normal	Difference	Most rain since
Windsor	100.8	55.6	45.2	2009
Muskoka	68.0	36.9	31.1	2004
Hamilton	79.4	48.6	30.8	2010
Waterloo	73.0	45.1	27.9	1991
Toronto Pearson	62.8	36.7	26.1	2009

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

Location	Snowfall	Normal	Difference	Least snow since/ Most snow since
Wawa	18.6	43.1	-24.5	1998 (Least snow since)
Red Lake	60.8	26.3	34.5	2004 (Most snow since)
Waterloo	53.0	24.1	28.9	2008 (Most snow since)

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

Location	Precipitation	Normal	Difference	Driest since/ Wettest since
Elliot Lake	26.3	66.4	-40.1	2010 (Driest since)
Wawa	30.8	63.7	-32.9	2010 (Driest since)
Waterloo	125.2	69.9	55.3	1976 (Wettest since)
Petawawa	104.4	60.4	44.0	2008 (Wettest since)
Hamilton	116.6	74.8	41.8	2004 (Wettest since)
Peterborough	106.4	65.0	41.4	1980 (Wettest since)
Windsor	116.0	75.0	41.0	2008 (Wettest since)
London	118.1	78.4	39.7	1985 (Wettest since)
Toronto Pearson	91.4	57.1	34.3	1998 (Wettest since)
Trenton	105.5	72.4	33.1	2008 (Wettest since)
Muskoka	99.0	74.1	24.9	2008 (Wettest since)

Note: The normal period used is the 1971-2000 Climate Normals

Media: For more information, please contact:

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