They say if you don’t like the weather in Alberta, wait five minutes—and rapid changes in conditions this summer have forced the province to live up to its reputation.
Alberta has had a spectacular few weeks of weather, ranging from hot and muggy to torrential downpours, and now the conditions Edmontonians had hoped to avoid have arrived.
Wildfire smoke is now pouring down from the Northwest Territories and rapidly degrading air quality.
As of 2 p.m. Monday, there are 202 active fires burning in the NWT, covering more than 777,000 hectares—an area larger than the city of Edmonton.
All but seven of the fires are out of control, and warm, dry and windy weather in the Northwest Territories is expected to increase the risk of wildfires. The largest of the fires near Fort Simpson has been burning since June 26 and now covers 55,403 hectares.
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Just before noon Monday, Environment Canada issued an air quality warning for all of Alberta north of Red Deer, saying air quality and visibility could change quickly over short distances and from hour to hour.
In Edmonton, where smoke is expected to persist into Tuesday, the Air Quality Index (AQHI) was expected to reach 10+ by Monday afternoon.
Wildfire smoke over downtown Edmonton and the North Saskatchewan River Valley on Monday, July 20, 2026.
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The AQHI indicates the level of pollution in a community. A score of 1–3 is low risk, 4–6 is moderate risk, 7–10 is high risk, and more than 10 is very high risk.
People most likely to be affected by wildfire smoke should reduce or reschedule strenuous outdoor activities and seek medical attention if symptoms occur, according to Environment Canada.
This includes people age 65 and older, pregnant women, infants and children, people with existing medical conditions or chronic health conditions, and people who work outdoors.
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When indoors, keep windows and doors closed as much as possible to prevent wildfire smoke from getting inside.
Environment Canada recommends using the highest quality air filter your ventilation system can handle and/or a certified portable air purifier that can filter fine particles.
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However, when extreme heat combines with poor air quality, Environment Canada said staying cool is a priority.
Long-term exposure to wildfire smoke harms health
In conditions of heavy smoke, the health of every person is at risk, regardless of his age and health status.
Poor air quality is associated with poor health outcomes and the development or worsening of some chronic diseases.
But you don’t have to wait until the sky turns deep orange and the smell of a burning fire fills the air to take steps to protect your health—the damage can begin long before then.
Wildfire smoke over downtown Edmonton and the North Saskatchewan River Valley.
Global news
An AQHI of five or more can still lead to damage and inflammation as fine particles from fires, chemicals and pollution—so small they can’t be seen—are inhaled deep into lung tissue, Alberta Lung said.
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The health agency advises that when the AQHI reaches five or higher, people should consider limiting time outdoors or wearing an N95 mask, and once inside, take steps to eliminate contaminants, such as changing clothes, washing your face and using air filters through HEPA or HVAC systems.
Health experts said very small particles can be absorbed into the bloodstream and affect a person’s brain.
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Long-term health effects of poor air quality due to wildfires
Many people with asthma or other chronic illnesses, as well as infants, young children, pregnant women and older adults, are less exposed to smoke and other air pollution than otherwise healthy people.
Children are particularly susceptible due to their biology, both now and in the long term. Children have smaller respiratory systems and breathe faster than adults, so they have higher concentrations of pollution than adults, and over time this can affect their development or lead to asthma.
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In addition to asthma, studies have shown that wildfire smoke is associated with increased hospital visits in both children and adults with other lung diseases such as viral infections, pneumonia and chronic obstructive pulmonary disease (COPD), as well as heart attacks and strokes.
Some of the first signs that someone may be reacting to smoke particles include:
- Itchy eyes
- Sore throat
- Cough
- Nasal congestion
- Nasal congestion
- Headache
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What is in forest fire smoke?
Although wildfires are a natural part of the boreal forest ecosystem, a growing body of research documents that climate change caused by the burning of fossil fuels is making them larger and more intense, and contributing to even more air pollution.
Fires release more fine pollution particles known as PM2.5, and this is a particularly harmful component of wildfire smoke. It is small enough to penetrate deep into the lungs and can have serious long-term health effects. PM 2.5 comes from a variety of sources, including power plants and vehicles.
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Canadians can track wildfire smoke concentrations by particle size using the Fire Works Canada Environment and Climate Change map.
A 2024 study estimates that the number of smoke-related deaths from wildfires linked to climate change has risen sharply since the 1960s.
Using mathematical modeling, the study estimated that about 12,566 annual wildfire smoke-related deaths in the 2010s were linked to climate change, compared with about 669 in the 1960s, when there was much less carbon dioxide concentrated in the atmosphere.
When converted to the total proportion of wildfire smoke deaths, the study estimates that about 13 percent of estimated excess deaths in the 2010s were attributable to climate change, compared with about 1.2 percent in the 1960s.
Last year, Environment Canada changed its color-coded air quality index to improve the way the public communicates and understands the health risks associated with air quality. The change was driven by a “record number” of AQHI 10+ scores in the 2023 bushfire season.
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— with files from The Canadian Press and Emily Mertz