Hurricane season occurs every year from June 1 to November 30 in the North Atlantic. Often, the most powerful hurricanes happen later in the season — during the late summer and early fall months.
Hurricanes tend to occur when the Atlantic waters are warm enough to develop and form a tropical cyclone, which then develops into a hurricane.*
*Source: Hurricanes: Information & Facts, 2021
Southern Ontario can experience the remnants of hurricane systems that carry large amounts of moisture from the Atlantic Ocean and the Gulf of Mexico. This moisture, when combined with large fall and frontal weather systems capable of triggering large amounts of rainfall on already saturated ground, can be a recipe for a flooding disaster.
What is TRCA Doing to Mitigate Fall Flood Risks?
Implementing flood plain management policies is the primary tool in reducing exposure to flood risk.
Another important tool is Toronto and Region Conservation Authority’s (TRCA) Flood Forecasting and Warning Program. TRCA issues flood messages to local municipalities, school boards, the media and members of the public who self-subscribe. The program operates 24 hours a day, seven days a week.
SIGN UP TO RECEIVE TRCA FLOOD MESSAGES
Flood duty officers monitor conditions across TRCA’s jurisdiction and provide local agencies and the public with notice, information, and advice so that they can respond during severe rainfall events that could lead to flooding.
Visit TRCAgauging.ca to view real-time water levels in your local river or stream.
TRCA is also responsible for operating and maintaining a suite of flood control infrastructure, including dams and channels.
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TRCA’s skilled and experienced staff use their expertise to help plan and manage the Greater Toronto Area’s watersheds now and for years to come.
Staying at the forefront of technology and preparedness is essential, and will help TRCA continue to learn from the past and protect cities well into the future.
LEARN HOW TO PREPARE FOR FLOODING
History of Hurricanes
in the Greater Toronto Area
Hurricane Hazel struck the Greater Toronto Area on October 15, 1954, pouring 285 millimetres (11.23 inches) of rain in 48 hours and causing major flooding. Bridges and streets were washed out, homes were washed into Lake Ontario, and 81 people were killed.
The Toronto area had experienced above average rainfall, especially in the two weeks prior to Hazel’s arrival. This saturated the ground and prevented Hazel’s rainfall from infiltrating the soil, which became a factor in the subsequent flooding.
Hurricane Hazel set the standard in Ontario. This event became a part of Ontario’s flood modelling criteria, described as the worst possible scenario, or the Regional Storm.
- For more information on flood plain management and mapping, visit our Frequently Asked Questions.
- For more information on Hurricane Hazel, visit hurricanehazel.ca.