THUNDER BAY – WEATHER – While Dryden, Kenora, and Fort Frances are all under Heat Warnings, Thunder Bay is starting off cool and damp this morning, but summer warmth is on the horizon.

As Thursday unfolds, sunshine and rising temperatures will take over, leading into a more unsettled, and potentially stormy end to the week.

Hopefully nothing like happened on Saturday in Westfort where a major microburst storm has left many trees down, and damaged homes and property. A sure sign that climate change is real.

Residents should prepare for a shift from comfortable conditions today to a humid and gusty Friday.

Today’s Weather Overview

Current Conditions

At 7:00 AM EDT, Thunder Bay Airport is reporting mostly cloudy skies with a temperature of 9.1°C and a dew point of 8.9°C, making for 99% humidity—a calm and humid start to the day. Winds are light from the west at 5 km/h, and the barometric pressure is 101.7 kPa and rising, indicating clearing conditions. Visibility remains excellent at 32 km.

Today will turn sunny, with temperatures climbing to a high of 23°C and a humidex of 25°C. The UV index will hit 9, classified as very high, so sun protection is important, especially for midday outdoor activities.

Tonight, skies will remain clear, becoming partly cloudy overnight with a low of 11°C—ideal sleeping weather.

Tomorrow’s Forecast

Expected Conditions

Friday, July 4: A dramatic weather shift arrives with cloudy skies and a 60% chance of showers, along with a risk of thunderstorms. The high will reach 26°C, but it will feel like 33°C due to high humidity. Strong east winds at 40 km/h, gusting up to 70 km/h, will make for a blustery morning before easing by afternoon.

Friday night stays cloudy with a 40% chance of showers and a warm low of 18°C.

Saturday, July 5: Rainy weather continues with cloudy skies and a 60% chance of showers. Temperatures will top out at 24°C, with an overnight low of 16°C.

Sunday, July 6: The weekend ends on a brighter note with a mix of sun and cloud and a cooler high of 22°C. Expect cloudy periods overnight, dipping to 11°C.

Wardrobe Recommendations

• Today: Light layers are perfect for the cool start and warming afternoon. Don’t forget sunglasses and sunscreen, especially during midday.

• Friday: Waterproof outerwear and wind-resistant jackets will be essential. Consider securing loose outdoor items due to gusty winds.

• Saturday: Bring a rain jacket or umbrella. Humid conditions persist, so dress in breathable materials.

• Sunday: Comfortable outdoor wear with layers for the cooler morning and evening.

Weather Trivia

Thunder Bay’s proximity to Lake Superior means the city often experiences large temperature swings. For instance, it’s not uncommon for July mornings to start under 10°C, as we saw today, only to climb well into the 20s by afternoon. This lake effect can dramatically influence local weather patterns year-round.