Weather &
air quality
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Air temperature
"Hey virtual assistant, what's the weather like today?"
The outside temperature influences the clothes we wear or whether today is a beach day. But that's not all. Temperature affects our lifestyles, too. Rising temperatures can lead to changes in energy consumption, water usage, and transportation patterns. Temperature is also a key indicator of climate change.
High temperatures determine if plants and animals can thrive, impact how we design buildings and transportation, and shape the way we use our resources. Outdoor activities can become dangerous in high temperatures, and people are much more likely to suffer from heat exhaustion or heat stroke.
Since warmer air has a higher capacity to hold water, increasing evaporation will also lead to more humid conditions. This has a compounding effect on how humans experience heat, which makes health impacts more likely. [1]
Persistently high temperatures can also increase the risk of drought, which can impact the agricultural sector and increase the risk of wildfire.
High temperatures can lead to more thunderstorms, which means increased risks of flash flooding, lightning, hail and perhaps even tornadoes.
Show your stripes
Climate stripes are a way of visualizing how average temperatures have changed over time. Each stripe represents the temperature of a year, colour-coded from blue (cooler than average) to red (hotter than average).
These stripes represent the temperature in Ontario from 1871-2022.
How hot is the hottest day?
Here is how the hottest day (the warmest daytime temperature) is expected to change for the Grey-Bruce health unit region:
Present (1991 – 2020)
31.9 °C
Near future (2031 – 2060)
Less warming (SSP2-4.5): 34.0 °C
More warming (SSP5-8.5): 34.3 °C
Far future (2071 – 2100)
Less warming (SSP2-4.5): 35.4 °C
More warming (SSP5-8.5): 37.8 °C
How many hot days will we have?
Most of us can agree that a day with a high of more than 30 °C is a very hot day.
Here is how the number of hot days per year is expected to change for the
Grey Bruce health unit region:
Present (1991 – 2020)
7 Days
Near future (2031 – 2060)
Less warming (SSP2-4.5): 17 days
More warming (SSP5-8.5): 22 days
Far future (2071 – 2100)
Less warming (SSP2-4.5): 31 days
More warming (SSP5-8.5): 60 days
The effects of hot days can feel even worse when there’s no relief from the heat, as in during a heat wave. Heat waves are defined as three or more consecutive days with a maximum temperature greater than 30 °C.
In the recent past, from 1976 – 2005, the Owen Sound region experienced a heat wave roughly every other year. In the highest warming scenario, this could increase to nearly five heat waves per year by 2080. [2]
Prolonged exposure to high temperatures can increase the risk of heat stroke and heat exhaustion. For vulnerable populations, such as elderly people or people with certain health conditions, extreme heat can even be life-threatening.
The cost of a heat wave
The economic impact of a heat wave can be substantial, including costs from increased energy consumption and agricultural losses. But the biggest cost comes from the toll that increased heat takes on human health.
Heat waves increase heat-related hospitalization and healthcare costs. Heat can also undermine labour productivity, especially in sectors where work takes place outdoors or in poorly cooled spaces.
More frequent heat waves and hot days will also lead to more deaths. The heat wave that struck British Columbia in June 2021 contributed to the deaths of more than 600 people, making it the deadliest disaster in the province’s history. [3]
Modelling from the Canadian Climate Institute estimates that by mid-century, under the high-emissions scenario, there will be an addition 400 heat-related deaths in Canada each year. This climbs to 790 deaths annually by the end of the century. [4]
The cost of lost life and reduced quality of life adds up: it’s projected to total between $3.0 billion and $3.8 billion by mid-century, and between $5.2 billion and $8.5 billion by the end of the century, depending on the amount of warming. [4]
Ice days and very cold days
Ice days describe the number of days where temperatures
remain below freezing for the entire day.
Present (1991 – 2020)
64 days
Near future (2031 – 2060)
Less warming (SSP2-4.5): 46 days
More warming (SSP5-8.5): 39 days
Far future (2071 – 2100)
Less warming (SSP2-4.5): 35 days
More warming (SSP5-8.5): 14 days
Meanwhile, the number of very cold days (with a temperature less than -15 °C)
are shrinking from around 19 days presently to between one to four days
by the end of the century.
Winter traditions
on thin ice
Lacing up skates for a game of pick-up hockey on a backyard rink.
Sitting on a deeply frozen lake, anticipating the thrill of a fish taking the bait.
Putting the button nose on Frosty, waiting for him to come to life.
These are just some of the quintessential parts of winter in the Saugeen-Bruce region. With increasingly warm winters and diminishing ice and cold days, these pastimes could soon be obsolete.
In the most intensive warming scenario, there may be as few as 14 days per year where temperatures remain below freezing all day – and, if these days aren’t consecutive, it may not be cold to ice over rinks and lakes, or keep snow creations from melting away.
Precipitation
A warmer atmosphere can hold more moisture. More moisture means more frequent and intense heavy rain and snow events.
This is particularly true for the region around the Great Lakes. For example, overall precipitation in the United States increased 4% from 1901 to 1915, but the Great Lakes region saw an almost 10% increase in that same time. Most of that precipitation came as unusually large events. [5]
In the future, precipitation will likely redistribute across the seasons. Winters and springs will get wetter, while summer precipitation should decrease by 5-15% for most of the Great Lakes region by 2100.
For example, the Grey Bruce region currently receives about 74 mm of precipitation in February.
By the turn of the century, this is projected to increase by 19 to 30%, to between 88 and 97 mm.
Hover or click on the graph to see individual values. Tap the legend to highlight or toggle scenarios. Find out more about what each scenario means here.
Flooding
The severity of a flood depends both on the amount of water that accumulates and the land’s ability to deal with the water.
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Some materials become saturated more quickly than others. Soil has a huge capacity for soaking up water.
Uncultivated land is generally more absorbent than soil that has been tilled for crops, so farm areas can be more prone to flooding than forests. This flooding can then further increase soil erosion in agricultural areas.
Concrete, stone and other impermeable materials are some of the least absorbent surfaces. This makes them ideal for constructing buildings to keep us dry, but also means that urban areas can face severe impacts from increased precipitation and flooding.
Extreme rain events can overwhelm storm drains, causing flash flooding. Heavy snowfall can disrupt transportation and even cause damage to building roofs. [6]
Those living in low-lying and flood-prone areas can face property damage and even displacement from their homes due to intensified flooding.
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Conservation authorities maintain accurate maps of floodplains and use them to provide
real-time flood forecasting and risk assessment.
Drought
Drought is a shortage of precipitation that lasts for some extended period. Droughts can last for weeks, months, or years, though it can sometimes be difficult to clearly define when a drought starts or ends.
Western Canada (particularly the southern Canadian Prairies) are more susceptible to drought, but droughts do also occur in Ontario. Between 1920 and 1999, southern Ontario experienced seven major droughts (1930, 1933, 1934, 1936, 1963, 1998, and 1999). [7]
Did you know...
Evapotranspiration
=
Evaporation (movement of water directly to air from soil and water bodies)
+
Transpiration
(evaporation of water into the atmosphere through plants)
As global temperatures increase, a process known as “evapotranspiration” is expected to increase, and with it the risk of drought increases. This could be balanced by increases in precipitation, but it is dependent on how much temperatures rise. [8]
As a result, it’s difficult to predict how the Saugeen-Bruce area will be affected by drought in the future. Under the high emissions scenario, it is likely that the region may experience low to moderate annual water deficits towards the end of the century. [9]
Drought can have negative impacts on agriculture by harming crop yields, reducing the amount of food available to livestock, raising production costs, and affecting soil health.
Drought can also impact human health: lower water levels can increase the concentration of contaminants in recreational and drinking water, while a dry period followed by extreme rainfall can increase the risk of food and water borne illnesses. [8]
Extreme weather
While climate describes long-term trends, weather is what we experience day-to-day.
The smaller scale, turbulent nature of weather means that it can be very difficult to precisely predict how things will change in the long term.
There’s evidence to suggest that a warmer climate may make weather even harder to predict. When air at the planet’s surface is warmer, the changes in the vertical arrangement of heat and cold in the atmosphere can fuel faster growth of eddies (swirls that can lead to storms) in the lowest atmospheric layer. [10]
Snowstorms
In general, snow cover has decreased by 5-10% across Canada from 1981-2015. [11]
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This is particularly true for the Saugeen Bruce region, which routinely experiences snowstorms that blanket the area in more than a metre of the cold white stuff. The region is located within Lake Huron’s “snow belt,” so named for the considerable amount of lake-effect snow that it receives.
Warmer winters promise to lead to warmer lake temperatures and less ice cover—ideal for creating bigger and more intense lake effect snowfalls. This could mean even more shoveling in the winter!
The recipe for lake-effect snow on the shores of Lake Huron
Damaging weather events
Severe storms such as thunderstorms, ice storms, and tornadoes can lead to power outages, damage to buildings and infrastructure, disruption of critical services and bodily harm—or even mortality.
The variables associated with extreme weather, such as high winds, freezing rain, and extreme localized precipitation, are very difficult to model within climate change projections. [12]
The storms, which tend to be smaller in scale, are difficult to capture within the large-scale climate models. Local environment can play a large role as well: wind speed, for example, can vary based on the land or water that it travels over. [13]
One recent study has shown that severe thunderstorm winds have intensified over the past 40 years, and that climate change is contributing to the increase.
The study looked at non-tornadic thunderstorm winds, also known as “straight line winds” in the central United States. Researchers found that the winds have intensified at a rate of 13% per degree Celsius of warming, more than the 7.5% per degree intensification that’s predicted.
Their simulations also suggest that such storms have grown to affect nearly five times as much area over the past four decades.
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Scientists note that the complex processes at play in the atmosphere could also cut back on the overall number of storms, suppressing the weaker ones. That means that the ones that do form can tend to be more extreme. [14]
Did you know...
a derecho (deh-REY-cho) is a long-lived, fast-moving wind storm accompanied by a band of thunderstorms. A derecho can cause similar destruction to a tornado. Unlike a tornado, though, a derecho’s winds are straight.
A derecho swept across southern Ontario and southwestern Quebec on May 21, 2022. The destructive winds of up to 190 km/h caused widespread damage along its 1,000-kilometre path, killing 12 people and leaving nearly 900,000 homes and businesses without power. [15] [16] [15]
Derechos in Canada are extremely rare: the one prior to the 2022 event occurred in 1999. Because they are so infrequent, it’s difficult to tell whether they are becoming more common. [15]
But researchers say the ingredients necessary to form derechos—namely heat and moisture—may come together more often thanks to climate change.
Aerial images shot from a drone show the aftermath of the 2022 storm in Uxbridge, Ont. (Sue Reid/CBC News)
Improving tornado detection and extreme weather prediction.
Spotlight on Northern Tornadoes Project
Founded in 2017 at Western University with support from ImpactWX, the NTP is a community endeavour involving partners and collaborators such as the University of Manitoba, Pelmorex’s The Weather Network, and Environment and Climate Change Canada.
Tornadoes, despite their awesome power, are much smaller in scale compared to other phenomena that meteorologists forecast. This makes them very difficult to predict.
Tornadoes are also challenging to detect. Doppler weather radars usually don’t have the ability to resolve them, and they can’t be seen with satellite or lightning data. That’s why NTP relies heavily on supplementing their surveys through crowdsourcing data and citizen science.
The Northern Tornadoes Project (NTP) aims to:
Better detect tornado occurrence throughout Canada
Improve severe and extreme weather prediction
Mitigate harm to people and property
Investigate future implications due to climate change
Be a citizen scientist: The NTP has a goal of recording every tornado that occurs in Canada – something that can only be achieved with eyewitness observations and damage reports from the public.
Visit The Northern Tornadoes Project to send in photos, videos, or descriptions if you think you may have seen a tornado.
Source: https://glatos.glos.us/map
You can view all NTP investigated events in their publicly available map.
Forest fires
In 2023, more than 45 million acres of Canadian
forest burned down.
That’s more than twice the previous modern single-year record of wildfires, which was set in 1989, when 19 million acres burned across the country. It’s also more than 15 times the total area of Bruce, Huron, and Grey counties, which stretches from the tip of Tobermory down to Grand Bend and across to Collingwood.
Most of the forest fires were located in Canada’s remote north, in the boreal forests of the Yukon, Nunavut, and Northwest Territories. Forest fires may not usually pose a direct threat to the Saugeen-Bruce region, but the smoke from those fires knows no boundaries.
The toxic air travelled across the country, sweeping across our region, casting our shores in an eerie sepia tone. The smoke even made it as far as Greenland, Spain and Britain.
Effects of wildfire smoke on lungs
FireSmoke Canada is the Canadian portal for information about wildland fire weather and smoke. The smoke forecast map provides high resolution, interactive forecasts of smoke particles at ground level from wildfires.
Fire season—the annual period during which forest fires are likely to start, spread, and cause damage—is projected to grow longer as the climate warms. By 2100, the fire season in certain forest areas may be more than a month longer. [17]
Reigning in the changing climate is the biggest factor in managing fires going forward. Good forest and land management practices are the next best strategy.
“Our lives are a blink of the eye in the life of the forest. We told ourselves we were in control. But some things are just more powerful than people. And fire burning in the boreal forest under 80-kilometer-an-hour winds is one of those things.”
- Mike Westwick, fire information officer
Read more about Canada’s year of fire in the New York Times. [18]
Air quality
On a warm, smoggy day, stepping outside can be unsettling.
The air feels heavy, thick and oppressive, laden with pollutants. In contrast, taking a walk through a forest can be rejuvenating, with air that’s crisp and pure.
Clean air is essential for our wellbeing. Poor air quality can lead to a range of respiratory issues, such as asthma, bronchitis and other chronic conditions. Long-term exposure to pollutants can come with an increased risk of diseases or even death.
How climate change will affect the quality of the air we breathe is an active area of study. We know that the processes that release greenhouse gases into the atmosphere also often emit other harmful pollutants. Increased heat and wildfires can also increase the concentration of pollutants in the air.
Meet the pollutants
There are many kinds of chemicals and particles that are considered pollutants, but research suggests that there are four main types that may be particularly affected by the changing climate.
Nitrogen oxides (NOx) are a mixture of gases composed of nitrogen and oxygen. They are produced during fossil fuel combustion, such as the burning of coal, oil, or natural gas, or from car emissions. Nitrogen oxides can react with other chemicals in the air to form particulate matter and ozone. They also interact with water, oxygen, and other chemicals in the atmosphere to form acid rain. [19]
High concentrations of O3 and PM2.5 can cause both sudden-onset breathing problems, particularly for those with asthma, as well as chronic health issues and even death from long-term exposure. [23]
Increases in these pollutants often coincide with heat waves, when the air stagnates from lack of atmospheric movement. [24]
The combination of high heat and poor air quality can lead to severe adverse impacts on public health. When it’s hot, we tend to breathe in more air—which also means breathing in more pollutants. We also retain more water, which can make it difficult for our kidneys to remove toxins from our bodies. [25]
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How polluted is the air today?
You can view real-time and historical data on air quality measurements locally and around the world with the World Air Quality Map. Monitoring stations report on particulate matter, ozone and more.
Clearing the air
“Ontario’s coal phase-out program that cleaned our province’s air stands out as one of the largest and most successful GHG and pollution reduction policies worldwide.”
– Green Ribbon Panel [26]
When was the last time we had a smog day? If you live in Ontario, the answer to that question is now nearly a decade ago.
Starting in 2003, Ontario began to phase out coal-fired electricity generation plants. To achieve a cleaner energy grid, low greenhouse gas (GHG)-emitting sources of generation were added to the supply mix. The majority of this new power came from nuclear energy. By 2014, all the coal plants had been phased out.
This had a dramatic impact on the quality of Ontario’s air. The number of smog days declined from 53 in 2005 to zero in 2015. Now, Ontario’s electricity grid is more than 90% GHG emissions free.
Not only has this had a major impact on human health, but it’s also provided economic advantages. The Province of Ontario regularly uses the cleanliness of its grid as a means to attract potential businesses to the province.
