🌦️ A cool, damp start to the week as a low-pressure system tracks across Northern Ontario, bringing periods of rain and brisk winds
Current Conditions – 6:00 AM EDT, Thunder Bay Airport
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Temperature: 2.0°C
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Condition: Partly Cloudy
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Pressure: 101.0 kPa (Rising)
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Dew Point: 1.1°C
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Humidity: 94%
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Wind: WSW 6 km/h
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Visibility: 24 km
Thunder Bay – WEATHER – A chilly morning under partly cloudy skies greets Thunder Bay as a developing system approaches from the west. Temperatures will climb slowly through the morning, with cloud cover increasing and rain arriving later in the day.
A transitional weather pattern is in full swing for Thunder Bay. After a mild and dry stretch, a strong low-pressure system brings two days of steady rain, gusty easterly winds, and a noticeable temperature drop by midweek. The latter half of the week looks cooler but more stable, with clearing conditions and seasonal highs near 6–8°C by Thursday.
🌡 4-Day Temperature and Precipitation Summary
| Date | Forecast | High | Low | Rain/Snow Potential | Wind |
|---|---|---|---|---|---|
| Mon 20 Oct | Increasing cloud, rain late | 9°C | 8°C | 🌧️ 10–15 mm | E 20–40 km/h |
| Tue 21 Oct | Rain continues | 7°C | 3°C | 🌧️ 5–10 mm | NE 20–40 km/h |
| Wed 22 Oct | Cloudy, scattered showers | 7°C | -1°C | 🌦️ 30–40% | NW 20 km/h |
| Thu 23 Oct | Mix of sun and cloud | 8°C | -2°C | ☀️ Mostly dry | Light |
Today – Monday, October 20
Expect a mix of sun and cloud early, but skies will quickly thicken as moisture from the approaching low arrives.
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Chance of Showers: 40% by early afternoon
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Rain Begins: Late this afternoon
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Wind: Becoming east 20 km/h gusting to 40 km/h this afternoon
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High: 9°C
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UV Index: 2 or low
By late day, periods of rain will become steady, marking the start of a soggy couple of days across Northwestern Ontario.
Tonight
Rain will continue through the evening and overnight hours.
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Rainfall: 10–15 mm possible
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Wind: Southeast 20 km/h gusting to 40, easing after midnight
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Temperature: Steady near 8°C
The evening will feel damp and cool, but temperatures will remain above freezing overnight.
Tuesday, October 21
More rain is expected throughout the day as the low-pressure system lingers over the Great Lakes region.
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Rainfall: Additional 5–10 mm
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Wind: Becoming northeast 20 km/h gusting to 40 km/h in the afternoon
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Temperature: Steady near 7°C
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UV Index: 1 or low
The combination of persistent rain and a northeast breeze will make it feel colder than the thermometer reads.
Tuesday Night
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Weather: Cloudy with a 60% chance of lingering showers.
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Low: +3°C
Showers taper off gradually overnight as cooler air starts to filter in behind the departing system.
Wednesday, October 22
Cloudy skies remain dominant through midweek.
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Weather: Overcast with a 40% chance of scattered showers.
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High: 7°C
By evening, temperatures will begin to drop, and a few flurries could mix in as cooler air settles over the Lake Superior basin.
Wednesday Night
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Weather: Cloudy with a 30% chance of rain showers or flurries.
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Low: -1°C
🧤 Local Impact Notes
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Travel: Wet roads and reduced visibility today and Tuesday — allow extra time for commutes.
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Outdoor activities: Monday evening and Tuesday are not ideal — expect steady rain and gusty winds.
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Heating needs: Cooler mornings midweek may bring the first furnace start-ups for many homes.
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Snow potential: A brief mix of rain and flurries is possible Wednesday night, though accumulation is unlikely in town.
