July 19, 2026: Thunder Bay Faces Widespread Wildfire Smoke and Very Poor Air Quality
THUNDER BAY — Widespread wildfire smoke is creating very poor air quality and sharply reduced visibility across Thunder Bay this Sunday morning.
Environment Canada and the Province of Ontario have issued an orange air-quality warning, indicating a high impact with high forecast confidence. Visibility at Thunder Bay Airport was only 1.6 kilometres at 9:00 a.m. EDT.
Showers may provide temporary improvement, but smoke is expected to remain a concern through Monday. Residents are advised to limit outdoor activity, monitor symptoms and take steps to keep indoor air as clean as possible.
Today’s Weather Overview
Current Conditions
At 9:00 a.m. EDT on Sunday, July 19, Thunder Bay was reporting smoke and a temperature of 15.5°C.
Humidity was high at 93 per cent, with a dew point of 14.3°C. Winds were light from the north at 2 km/h.
The barometric pressure was 101.7 kPa and falling, indicating that changing weather conditions are approaching.
Visibility was restricted to only 1.6 kilometres because of wildfire smoke.
Sunday Forecast
Skies will clear early this morning before a mix of sun and cloud develops. There is a 30 per cent chance of showers during the afternoon, along with a risk of a thunderstorm.
Widespread smoke will continue.
The temperature will reach 25°C, with the humidity making it feel closer to 30. The UV index will be 7, or high.
Tonight will be mainly cloudy with a 70 per cent chance of showers and a risk of a thunderstorm. Widespread smoke will remain in the area. The overnight low will be 15°C.
Extended Thunder Bay Forecast
Monday, July 20
Monday will be mainly cloudy with a 70 per cent chance of showers and a risk of thunderstorms.
Widespread smoke will continue to affect the city. Winds will become west at 30 km/h, gusting to 50, late in the morning.
The temperature will climb to 26°C, with a humidex of 32. The UV index will remain high at 7.
Monday night will be cloudy with a 40 per cent chance of showers. The low will fall to 13°C.
Tuesday, July 21
Tuesday will bring a noticeable drop in temperature.
A mix of sun and cloud is expected, along with a 30 per cent chance of showers. The daytime high will reach only 18°C.
Tuesday night will be clear and cool, with a low of 10°C.
Wednesday, July 22
Sunny skies return Wednesday, with a high of 24°C.
Wednesday night will remain clear, with an overnight low of 13°C.
Wildfire Smoke and Air-Quality Warning
The current smoke is coming from wildfires burning in Northwestern Ontario.
Environment Canada says the smoke is causing very poor air quality and reduced visibility. Conditions may change rapidly over short distances and from one hour to the next.
Although showers could temporarily clear some smoke from the air, poor conditions are expected to persist through much of the weekend and into Monday.
During periods of heavy smoke, everyone can be affected, regardless of age or health.
Common symptoms may include:
- Irritated eyes, nose or throat
- Headaches
- A mild cough
More serious symptoms can include wheezing, chest pain or a severe cough. Anyone who believes they are experiencing a medical emergency should seek immediate medical assistance.
People at greater risk include seniors, pregnant people, infants, young children, people with chronic health conditions and those who work outdoors.
Residents should avoid strenuous outdoor activity when smoke is heavy. Outdoor sports organizers, coaches and event officials should assess local air quality before proceeding with practices, games or public events.
Protecting Yourself from Wildfire Smoke
Keep windows and doors closed as much as practical and use the highest-quality air filter your home ventilation system can safely handle.
A certified portable air cleaner designed to filter fine particles may also improve indoor air.
People who must spend time outside should keep their exposure as brief as possible. A properly fitted N95 or equivalent respirator can reduce exposure to fine smoke particles, although it does not eliminate all health risks.
Check on family members, neighbours and others who may be more vulnerable to wildfire smoke.
When heat and smoke occur at the same time, keeping cool should remain a priority.
Wardrobe Recommendations
Light, breathable clothing will be most comfortable as temperatures climb toward 25°C today and 26°C Monday.
Carry a light waterproof jacket or compact umbrella because showers and thunderstorms may develop during the afternoon and evening.
A hat and sunglasses will still be useful during brighter periods, and sunscreen is recommended because the UV index will be high.
Anyone who must remain outdoors during heavy smoke should consider wearing a well-fitting N95 or equivalent respirator.
A sweater or light jacket will be helpful Tuesday evening, when temperatures are expected to fall toward 10°C.
Weather Trivia
Wildfire smoke can reduce visibility dramatically even when winds at ground level are very light. Thunder Bay’s north wind was only 2 km/h Sunday morning, yet smoke had reduced visibility to 1.6 kilometres.
Smoke movement is influenced by winds at several levels of the atmosphere, not only by the breeze experienced at the surface.
Summary: Thunder Bay weather for July 19, 2026: Widespread wildfire smoke, an orange air-quality warning, reduced visibility, thunderstorms and a detailed three-day forecast through Wednesday.
