Thunder Bay – WEATHER – Thunder Bay starts Tuesday cool, damp, and mostly cloudy, but the day is set to change quickly. At 7:08 AM EDT, the temperature was 12.9°C, with humidity at 100 percent and pressure falling. Despite the cool morning feel, a Yellow Heat Warning is now in effect for the City of Thunder Bay, with the first heat event of the season beginning today and continuing through Friday.
Today’s Weather Overview
Current Conditions
As of 7:08 AM EDT, Thunder Bay was reporting mostly cloudy skies and a temperature of 12.9°C. The dew point was also 12.9°C, with humidity at 100 percent, giving the morning a damp and heavy feel.
Winds were from the east-northeast at 12 km/h, visibility was 19 km, and the barometric pressure was 100.5 kPa and falling.
Today’s forecast calls for cloudy skies with a 40 percent chance of showers early this morning, then becoming a mix of sun and cloud. There is a risk of thunderstorms early this morning. The high will climb to 29°C, with a humidex of 34. The UV index is 9, or very high.
Yellow Warning — Heat
Impact Level: Moderate
Forecast Confidence: High
The first heat event of the season begins today.
Expected conditions include daytime highs of 29°C to 32°C, with some locations possibly reaching 33°C during the hottest stretch. Overnight lows will remain warm, generally between 16°C and 19°C, with some nights offering little relief as temperatures may stay between 18°C and 22°C.
Humidex values are expected to reach 36 to 41 during the event.
The heat warning is in effect today through Friday, with the hottest conditions expected today through Thursday. Hot and humid air may also cause air quality to deteriorate, with the Air Quality Health Index possibly approaching the high-risk category.
Tomorrow’s Forecast
Expected Conditions
Tonight: Thunder Bay will see a few clouds and a warm overnight low of 18°C.
Wednesday, July 1: Canada Day will bring increasing cloudiness early in the morning. Winds will become west at 30 km/h, gusting to 50 km/h, late in the morning. The high will reach 29°C, with a humidex of 31. The UV index is 8, or very high. Wednesday night will be cloudy, with a low of 16°C.
Thursday, July 2: Expect a mix of sun and cloud with a 30 percent chance of showers and a high of 30°C. Thursday night brings cloudy periods, a 30 percent chance of showers, and a low of 13°C.
Friday, July 3: The heat continues, with a 30 percent chance of showers and a high near 28°C. Friday night also carries a 30 percent chance of showers, with a low of 13°C.
Heat Safety
Extreme heat can affect everyone’s health. Check on older adults, people living alone, young children, outdoor workers, and anyone with health concerns.
Watch for early signs of heat exhaustion, including headache, nausea, dizziness, thirst, dark urine, and intense fatigue. Stop activity, move to a cooler place, and drink water.
Heat stroke is a medical emergency. Call 9-1-1 if someone has red, hot skin, confusion, dizziness, nausea, or a change in consciousness. Move the person to a cool place, remove extra clothing, and use cold water or ice packs while waiting for help.
Wardrobe Recommendations
Choose lightweight, light-coloured, loose-fitting clothing today and through the rest of the week. A wide-brimmed hat, sunglasses, and sunscreen are strongly recommended, especially with the UV index reaching very high levels.
Drink water before you feel thirsty, limit direct sun exposure, and plan outdoor work or exercise for the coolest parts of the day. Never leave children, vulnerable people, or pets inside a parked vehicle.
Weather Trivia
The humidex measures how hot the air feels when humidity is added to the actual temperature. That is why a 29°C day in Thunder Bay can feel much closer to the mid-30s when the air is humid and the body has a harder time cooling itself.
