Thunder Bay weather live forecast

Today's maximum temperature in Thunder Bay is expected to be 17°C. Select a day from the live weather forecast for Thunder Bay, Ontario, Canada for more weather parameters.

5-day weather forecast updated at 04:01 on Sunday 14th September 2025 GMT

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The 5-day weather forecast for Ontario (Thunder Bay) is provided by the Swiss meteorological agency, meteoblue. Find out more about our data sources.

Thunder Bay weather forecast by day

Below are the detailed weather forecasts for Thunder Bay for the next 5 days.

Thunder Bay weather for Sunday 14th September 2025

Expect broken clouds in Thunder Bay, Ontario with a maximum temperature of 17°C, maximum UV of 5 (Moderate) and 3 hours of bright sunshine. There are 0 mm of rainfall expected and a gentle breeze of 13 kph from the east.

  • 17°C maximum temperature17
    °C maximum temperature
  • 12°C minimum temperature12
    °C minimum temperature
  • Broken clouds
    broken clouds
  • 3 hours of bright sunshine3
    hours of sunshine
  • UV (maximum) index 5 (Moderate)5
    UV index (Moderate)
  • 0 mm of rainfall expected0
    mm of rainfall expected
  • No heat & humidity0
    no heat & humidity
  • Gentle breeze of 13 kph from the East13
    kph wind from E

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Thunder Bay weather for Monday 15th September 2025

Expect broken clouds in Thunder Bay, Ontario with a maximum temperature of 19°C, maximum UV of 4 (Moderate) and 5 hours of bright sunshine. There are 0 mm of rainfall expected and a light breeze of 11 kph from the east.

  • 19°C maximum temperature19
    °C maximum temperature
  • 12°C minimum temperature12
    °C minimum temperature
  • Broken clouds
    broken clouds
  • 5 hours of bright sunshine5
    hours of sunshine
  • UV (maximum) index 4 (Moderate)4
    UV index (Moderate)
  • 0 mm of rainfall expected0
    mm of rainfall expected
  • No heat & humidity0
    no heat & humidity
  • Light breeze of 11 kph from the East11
    kph wind from E

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Thunder Bay weather for Tuesday 16th September 2025

Expect broken clouds in Thunder Bay, Ontario with a maximum temperature of 23°C, maximum UV of 5 (Moderate) and 8 hours of bright sunshine. There are 0 mm of rainfall expected and a light breeze of 11 kph from the south-east.

  • 23°C maximum temperature23
    °C maximum temperature
  • 13°C minimum temperature13
    °C minimum temperature
  • Broken clouds
    broken clouds
  • 8 hours of bright sunshine8
    hours of sunshine
  • UV (maximum) index 5 (Moderate)5
    UV index (Moderate)
  • 0 mm of rainfall expected0
    mm of rainfall expected
  • No heat & humidity0
    no heat & humidity
  • Light breeze of 11 kph from the South-East11
    kph wind from SE

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Thunder Bay weather for Wednesday 17th September 2025

Expect isolated thunderstorms in Thunder Bay, Ontario with a maximum temperature of 23°C, maximum UV of 4 (Moderate) and 5 hours of bright sunshine. There are 2-5 mm of rainfall expected with 39% chance of some rain and a light breeze of 9 kph from the south.

  • 23°C maximum temperature23
    °C maximum temperature
  • 14°C minimum temperature14
    °C minimum temperature
  • Isolated thunderstorms
    isolated thunderstorms
  • 5 hours of bright sunshine5
    hours of sunshine
  • UV (maximum) index 4 (Moderate)4
    UV index (Moderate)
  • 39% chance of some rain39
    % chance of some rain
  • 2-5 mm of rainfall expected<5
    mm of rainfall expected
  • 23°C wind chill23
    °C wind chill
  • Light breeze of 9 kph from the South9
    kph wind from S

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Thunder Bay weather for Thursday 18th September 2025

Expect mostly cloudy with light rain in Thunder Bay, Ontario with a maximum temperature of 19°C, maximum UV of 1 (Low) and 2 hours of bright sunshine. There are 2-5 mm of rainfall expected with 40% chance of some rain and a gentle breeze of 14 kph from the north-east.

  • 19°C maximum temperature19
    °C maximum temperature
  • 13°C minimum temperature13
    °C minimum temperature
  • Mostly cloudy with light rain
    mostly cloudy with light rain
  • 2 hours of bright sunshine2
    hours of sunshine
  • UV (maximum) index 1 (Low)1
    UV index (Low)
  • 40% chance of some rain40
    % chance of some rain
  • 2-5 mm of rainfall expected<5
    mm of rainfall expected
  • No heat & humidity0
    no heat & humidity
  • Gentle breeze of 14 kph from the North-East14
    kph wind from NE

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Metric (°C / mm)  |  Imperial (°F / inches)

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