Ontario Weather Review - March 2006
Picture a seesaw…now you know what the month of March was like in Ontario. With some exceptions in Northern Ontario, temperatures rallied to within a degree or two of normal values, but only after numerous fluctuations. March began on the cool side, but by mid-month double-digit temperatures were recorded at many locations in Southern and Central Ontario – before cooling again. This seesaw of cool and mild temperatures was felt across the province, with the month ending on a mild note.
Precipitation was generally on the dry side. Few systems tracked across the province this month, providing very little rain and snow. The lack of snowfall was actually record-breaking in four locations. The only locations with significant precipitation above normal were Moosonee and Geraldton, where the recorded values exceeded more than twice the normal expected for March and set records.
Severe Weather
The first winter storm approached from the Midwest on March 2 and brought a mix of weather, mainly over southwestern Ontario. The most significant icing occurred over Windsor, which received five hours of freezing rain before that changed to ice pellets and snow. The freezing rain was even accompanied by lightning and thunder early in the morning! Regions over southern Lake Huron to London, and east to Niagara and Hamilton, saw heavy snow from the same system. There were reports of 10 to 20 centimetres by its conclusion.
Two low-pressure systems soaked much of southern Ontario over a period of two days (March 9-10). They spread a large swath of rain along the Highway 401 corridor from Windsor to the Golden Horseshoe, with 33 millimetres of rain falling over Kitchener and Elora. Rainfall warnings were also issued on March 10, from Manitoulin Island to North Bay, with Sudbury seeing the most rainfall at 22.2 millimetres. The first low created eight hours of freezing rain over Ottawa before changing to rain.
March 13 saw a battle between spring and winter as a deep Colorado low tracked across Sault Ste Marie. Very unseasonably warm and unstable air ahead of the storm brought record-breaking temperatures on March 12, with Toronto tying its all-time maximum temperature for that date of 15.2 Celsius, set in 1977. In addition, the first tornado watch of the year in Ontario was issued for Windsor and Sarnia as conditions were ripe for a potential tornado to form. This reminded us that summer severe weather was just around the corner.
Thunderstorms swept through most of southern Ontario the night of March 13, with many regions experiencing winds gusting to 80 to 90 kilometres per hour. The same storm brought snowfall warnings over an area from Wawa to Timmins. By the time the snow ended on March 14, most regions had received 20 to 30 centimetres.
A strong ridge of high pressure brought sunny skies and pleasant weather towards the end of March, when another storm approached Ontario with clouds and rain.
Unusual mean temperature readings:
| Location | Mean Temp | Normal | Difference | Warmest Since |
| Moosonee | -5.7 | -11.7 | 6.0 | 2000 |
| Pickle Lake | -5.7 | -10.0 | 4.3 | 2000 |
| Kapuskasing | -4.6 | -8.6 | 4.0 | 2000 |
| Timmins | -4.2 | -7.7 | 3.6 | 2000 |
| Geraldton | -5.9 | -9.0 | 3.1 | 2000 |
| Earlton | -4.0 | -6.9 | 2.9 | 2000 |
| Wawa | -3.8 | -6.6 | 2.8 | 2000 |
| Red Lake | -5.1 | -7.7 | 2.6 | 2000 |
| Sudbury | -2.8 | -5.3 | 2.5 | 2000 |
| Chapleau | -4.8 | -7.2 | 2.4 | 2000 |
| Elliot Lake | -1.9 | -4.2 | 2.3 | 2000 |
| Sioux Lookout | -4.7 | -7.0 | 2.3 | 2000 |
| Kenora | -3.4 | -5.6 | 2.2 | 2000 |
| Thunder Bay | -3.3 | -5.5 | 2.2 | 2000 |
Record snowfall readings (in centimetres):
| Location | Snow | Normal | Difference | Prior Record |
| Ottawa | 1.2 | 39.8 | -38.6 | 3.8 (1946) |
| Elliot Lake | 9.0 | 46.6 | -37.6 | 13.0 (2000) |
| Petawawa | 3.2 | 33.9 | -30.7 | 8.6 (1990) |
| Waterloo Wellington | 4.8 | 24.1 | -19.3 | 7.2 (1988) |
Record precipitation readings (in millimetres):
| Location | Snow | Normal | Difference | Prior Record |
| Moosonee | 104.1 | 31.7 | 72.4 | 87.1 (1966) |
| Geraldton | 70.6 | 30.5 | 40.1 | 65.6 (1988) |
Unusual precipitation readings (in millimetres):
| Location | Snow | Normal | Difference | Driest Since |
| Ottawa | 25.8 | 73.9 | -48.1 | 1996 |
| Sault Ste Marie | 18.7 | 60.1 | -41.4 | 1999 |
| Kingston | 36.8 | 75.3 | -38.5 | 2005 |
| Earlton | 27.0 | 59.1 | -32.1 | 2005 |
| Petawawa | 30.2 | 60.4 | -30.2 | 2001 |
| Trenton | 42.8 | 72.4 | -29.6 | 2005 |
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