Thunder Bay – Weather Desk – If you like the smell of smoke while you sweat, today is going to be your day in Thunder Bay. For the rest of us, Tuesday brings a difficult combination of extreme heat, wildfire smoke, and poor air quality.
The City of Thunder Bay is under two weather alerts this morning: an Orange Heat Warning and a Yellow Air Quality Warning. At 6:00 AM EDT, the temperature was already 25.5°C, with a humidex of 33 and visibility reduced to just 2 km in smoke.
Today’s Weather Overview
Current Conditions
At 6:00 AM EDT, Thunder Bay reported smoke with a temperature of 25.5°C. The dew point was 19.8°C, with humidity at 71 percent, making the morning feel hot and heavy.
Winds were from the west-southwest at 14 km/h, with pressure at 101.5 kPa and rising. Visibility was reduced to 2 km, showing just how thick the smoke is across the city.
Today’s forecast calls for a mix of sun and cloud with a 30 percent chance of showers early this morning and a risk of a thunderstorm. Widespread smoke is expected. Winds will become northwest at 20 km/h, gusting to 40 km/h late this morning.
The high will reach 34°C, with a humidex of 38. The UV index is 9, or very high.
Orange Warning — Heat
Impact Level: High
Forecast Confidence: High
A heat event continues for Thunder Bay.
Expected conditions include:
Maximum temperatures of 29°C to 35°C
Minimum temperatures of 19°C to 23°C
Humidex values of 36 to 40
The heat warning continues through this evening and may last into Wednesday for some areas.
Hot and humid air can increase health risks, especially for older adults, people living alone, infants and young children, outdoor workers, and those with medical conditions.
Yellow Warning — Air Quality
Impact Level: Moderate
Forecast Confidence: High
Wildfire smoke is causing poor air quality and reduced visibility in Thunder Bay. Poor air quality may persist through Wednesday for some areas.
As smoke levels rise, health risks increase. People may experience eye, nose, and throat irritation, headaches, or a mild cough. More serious symptoms can include wheezing, chest pain, or a severe cough.
People most likely to be affected include seniors, pregnant people, infants, young children, people with existing health conditions, and those who work outdoors.
Tonight and Wednesday
Expected Conditions
Tonight: Widespread smoke continues. Northwest winds at 20 km/h, gusting to 40, will become light this evening. The overnight low will be 18°C.
Wednesday, July 15: Thunder Bay will see sunny skies, becoming a mix of sun and cloud late in the afternoon. Local smoke remains in the forecast. Winds will be northwest at 20 km/h, becoming light in the afternoon. The high will reach 29°C, with a UV index of 9, or very high.
Wednesday Night: Clear skies are expected, with a low of 14°C.
Thursday, July 16: A cooler pattern begins, with a mix of sun and cloud and a 30 percent chance of showers. The high will be 25°C.
Heat and Smoke Safety
This is a day to take both heat and smoke seriously. When heat and poor air quality happen together, the first priority is to stay cool.
Drink water often, even before you feel thirsty. Avoid strenuous outdoor activity during the hottest part of the day. Close blinds or shades, use air conditioning or fans where possible, and move to a cooler indoor space if your home becomes too hot.
Keep windows and doors closed as much as possible when smoke levels are high. A good air filter or portable air cleaner can help reduce fine particles indoors.
If you must be outside, reduce heavy activity. A well-fitting N95-style respirator can reduce smoke exposure, though it does not remove all risk.
Watch for signs of heat exhaustion, including headache, nausea, dizziness, thirst, dark urine, and intense fatigue. Heat stroke is a medical emergency. Call 9-1-1 if someone has red, hot skin, confusion, dizziness, nausea, or a change in consciousness.
Wardrobe Recommendations
Wear lightweight, light-coloured, loose-fitting clothing today. A wide-brimmed hat, sunglasses, and sunscreen are important with the UV index at 9.
Anyone working outside should take frequent breaks, drink water, and watch for symptoms from both heat and smoke. If possible, shift outdoor work or exercise to cooler parts of the day.
Weather Trivia
Wildfire smoke can block some sunlight, but it does not make hot weather safe. Even with smoky skies, heat can build quickly, and the combination of high humidity, smoke, and poor nighttime cooling can put extra stress on the body.
Summary: Thunder Bay weather for July 14, 2026: Orange Heat Warning and Yellow Air Quality Warning in effect, with smoke, 26°C early, high 34°C, humidex 38, poor visibility, and very high UV.
