Thunder Bay – Weather – We are getting a glimpse of what is to come. There is a frost advisory in effect for Armstrong. This morning there is a cool take to the start of your Thunder Bay Sunday.
A cool and breezy Sunday morning in Thunder Bay leads into a calm and pleasant day, with sunshine dominating and highs near 19°C. But as we look ahead, unsettled weather is likely Monday with a risk of showers and thunderstorms, before warming up midweek.
Today’s Weather Overview
Current Conditions (as of 8:37 AM EDT – Thunder Bay Airport)
-
Temperature: 12.6°C
-
Condition: Partly Cloudy
-
Wind: E at 17 km/h, gusting to 28 km/h
-
Humidity: 75%
-
Dew Point: 8.3°C
-
Barometric Pressure: 102.6 kPa, rising
-
Visibility: 32 km
Sunday Forecast:
-
Morning: Partly cloudy skies with light northeast winds
-
Afternoon: Mainly sunny, with winds becoming calm
-
High: 19°C
-
UV Index: 7 — High, so sunscreen is still important even in cooler weather
Tonight:
-
Clear skies early, becoming partly cloudy late
-
Low: 10°C
Tomorrow’s Forecast
Monday, August 18
-
Cloudy with a 40% chance of showers late in the morning and into the afternoon
-
Risk of thunderstorms in the afternoon
-
Winds becoming east at 20 km/h
-
High: 17°C
-
UV Index: 5 — Moderate
-
Night: Overcast continues
-
Low: 13°C
Tuesday, August 19
-
Persistent cloudy skies
-
High: 19°C
-
Night: Cloudy
-
Low: 11°C
Wednesday, August 20
-
Mix of sun and cloud with warmer conditions
-
High: 23°C
-
Night: Clear skies, low: 12°C
👕 Wardrobe Recommendations
-
Sunday: Layer up in the morning — light jacket or hoodie — but switch to lighter clothing as the sun warms things up this afternoon.
-
Monday: An umbrella and waterproof jacket are smart choices with rain and thunderstorm potential.
-
Tuesday: Comfortable, casual layers are ideal for the continued cloudiness.
-
Wednesday: Warm-weather clothing returns — time for short sleeves again!
🌾 Outdoor Tips
-
Gardeners: The clear, calm weather tonight is great for cooling down your greenhouse or letting plants breathe.
-
Boaters & Hikers: Sunday is your best weather window — conditions are dry and visibility is excellent. Use caution on Monday if planning outdoor activities.
Weather Trivia
Did you know? Thunder Bay often records its coolest daytime highs of the month in the final week of August, as cold air from the north begins to influence the region more. However, this coming Wednesday’s 23°C high will be a pleasant and temporary break from that trend.
