Environment Canada

Environment Canada

September 04, 2007 13:01 ET

Environment Canada: Ontario Weather Review

August 2007

TORONTO, ONTARIO--(Marketwire - Sept. 4, 2007) -

A colour-coded map for Ontario for the month of August might show largely yellowish brown - for parched conditions. With very few exceptions, locations across the province remained, as has been true for most of the summer of 2007, warm and dry.

August temperatures generally remained slightly above normal, mostly by a degree or so, but the big story continues to be the lack of rainfall. Only some areas, for example Windsor and Sarnia in Southwestern Ontario, received much-needed moisture. Some areas experienced just a little below normal precipitation totals, but many areas received less than a third of the normal amount of precipitation. This included the most densely populated part of the province: Toronto airport barely surpassed 25% of its normal rainfall. Several communities surrounding Toronto, in fact, have put water-use restrictions in place.

Contrary to the hope of many, Environment Canada is forecasting a drier than normal September, except for the most northwestern part of the province.

Severe Weather

Severe weather-wise, August was a month that was notable for not having much that was notable. August is normally a fairly active month for damaging thunderstorms in Ontario - just last year, on August 2, there were 14 tornadoes - but this August was an exception. There were events scattered about the province that included some hail and gusty winds doing some tree damage, but not many powerful or long-lived events.

The month started off with a strong thunderstorm moving over the Kashechewan First Nation near the shores of James Bay during the early morning hours of August 1. The storm produced powerful wind gusts in excess of 100 kilometres per hour, which caused damage to a school and some homes in the community. This storm acted as an important reminder that any location in Ontario is susceptible to damaging thunderstorm activity. While the lower population density in the Far North makes it less likely for a strong thunderstorm to impact a community, these events do occur from time to time.

On the evening of August 26, a few powerful thunderstorms moved through portions of Northwestern Ontario. These did inflict some local damage, including some downed trees and damage done to a couple of sheds in the Deception Lake area between the Manitoba border and Kenora. A wind gust to 74 kilometres per hour was recorded at the Kenora Airport at approximately 10 p.m. CDT as these storms rolled through.

During the late afternoon and evening hours of August 29, a band of powerful thunderstorms moved through portions of Southern Ontario in advance of a cold front. In addition to heavy rain and some reports of pea-sized hail, strong, gusty winds knocked down some trees and power lines. Especially hard hit were parts of the Haliburton and Kawartha Lakes area, as well as parts of the Ottawa Valley.

The average number of tornadoes in Ontario over the past 25 years is 11. So far this year, three have occurred, with a few more events from earlier this summer still being investigated as being potentially tornadic in nature. However, the summer severe weather season, especially in Southern Ontario, does continue into early October. Therefore, the possibility exists that Ontario will still experience more significant thunderstorm activity before this season winds down.



Unusual temperature readings:

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Location Mean Temp Normal Difference Warmest since
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Toronto Pearson 22.4 19.9 2.5 2005
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Petawawa 19.6 17.6 2.0 2005
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Unusual precipitation readings (in millimetres):

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Location Precipitation Normal Difference Driest Since
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Waterloo 13.5 86.3 -72.8 2002
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Thunder Bay 24.0 87.5 -63.5 2006
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Wawa 39.0 99.5 -60.5 1990
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Toronto Pearson 20.8 79.6 -58.8 2002
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Elliot Lake 50.0 104.2 -54.2 2000
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Toronto City 29.8 79.6 -49.8 2006
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Trenton 28.5 77.1 -48.6 2006
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Wiarton 37.1 85.2 -48.1 1991
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Sault Ste. Marie 38.3 84.7 -46.4 1976
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Hamilton 41.0 80.6 -39.6 2004
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Peterborough 50.5 83.2 -32.7 2006
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Kingston 49.8 81.5 -31.7 2006
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Dryden 54.5 85.0 -30.5 2005
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Location Precipitation Normal Difference Wettest Since
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Windsor 159.4 79.7 79.7 1975
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Petawawa 122.4 81.1 41.3 2006
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Sarnia 117.5 77.1 40.4 1987
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Pickle Lake 128.4 94.9 33.5 2002
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Red Lake 117.0 86.0 31.0 2000
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Earlton 107.5 80.9 26.6 1993
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(Egalement offert en francais)

Contact Information

  • Environment Canada, Ontario Region
    Jack Saunders
    Communications Advisor/Media Relations
    (416) 739-4785
    Website: www.ec.gc.ca