Great Lakes Ontario Climate

Great Lakes Communities and Ecosystems at RiskThe Regionspacer
Confront the Challenge
• Climate in the Region
• The Report
• Technical Background
• For Teachers

Explore the Impacts
• Overview
• Migrating Climates
• Water Resources
• Sense of Place

Discover the Solutions
• Overview
• Solutions where we Live
• Reducing our Emissions
• Managing our Response
• Ten Personal Solutions

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Climate Change in Ontario
White Trilliun
Climate Projections
Forests & Wildlife
Human Health
Lakes, Streams, & Fish
Property and Infrastructure
Recreation & Tourism
Water Supply & Pollution
Wetlands & Shorebirds
Climate Solutions
Resources & Links

Climate Change Projections
Southern Ontario's relatively mild climate supports a productive agricultural sector while the tourism sector thrives as a result of Ontario's lakeshores and inland waters. Climate change threatens to change the character of this region, and many of southern Ontario's unique features.

The latest, most reliable projections of future climate change combine 100 years of historical data for Southern Ontario with the most up-to-date general circulation models of the Earth's climate system. In general Southern Ontario's climate will grow considerably warmer and probably drier during this century, especially in the summer. As a result of these changes, by 2030 summer in southern Ontario may feel more like current-day summer in upstate New York. Changes by 2095 are expected to be much more drastic however, with summers feeling like those today in Virginia.

Below is more detail on these projections. For a graphical depiction, see the Migrating Climates feature.

Projected Climate Changes in Ohio
Warmer Temperatures
A 3-7oC rise in winter temperatures and a 4-8oC rise in summer temperatures by the end of the century is projected.

Precipitation Changes Although average annual precipitation may not change much, an overall drier climate is expected because rainfall cannot compensate for the increase in evaporation resulting from greater temperatures. Thus Ontario may see drier soils and more droughts. Seasonally, winter precipitation is expected to increase by 10-30% while summer precipitation is expected to remain the same.

Extreme Events
Extreme heat will be more common, and the frequency of heavy rainstorms will increase.

Growing Season

The growing season in southern Ontario could be 4-7 weeks longer.

Ice Cover
Declines in ice cover on the Great Lakes and inland lakes have been recorded over the past 100-150 years, although this trend has been moderated in areas of lake-effect snow, it is expected to continue.

Photo Credits:
White Trillium -- Ohio Department of Natural Rescources, Mike Williams and Tim Daniel.
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