Thunder Bay weather live forecast

Today's maximum temperature in Thunder Bay is expected to be 23°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 Tuesday 2nd 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 Tuesday 2nd September 2025

Expect isolated thunderstorms in Thunder Bay, Ontario with a maximum temperature of 23°C, maximum UV of 5 (Moderate) and 6 hours of bright sunshine. There are 5-10 mm of rainfall expected with 80% chance of some rain and a gentle breeze of 16 kph from the south.

  • 23°C maximum temperature23
    °C maximum temperature
  • 13°C minimum temperature13
    °C minimum temperature
  • Isolated thunderstorms
    isolated thunderstorms
  • 6 hours of bright sunshine6
    hours of sunshine
  • UV (maximum) index 5 (Moderate)5
    UV index (Moderate)
  • 80% chance of some rain80
    % chance of some rain
  • 5-10 mm of rainfall expected<10
    mm of rainfall expected
  • No heat & humidity0
    no heat & humidity
  • Gentle breeze of 16 kph from the South16
    kph wind from S

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Thunder Bay weather for Wednesday 3rd September 2025

Expect cloudy with some rain in Thunder Bay, Ontario with a maximum temperature of 14°C, maximum UV of 1 (Low) and no hours of bright sunshine. There are 5-10 mm of rainfall expected with 81% chance of some rain and a moderate breeze of 24 kph from the north-west.

  • 14°C maximum temperature14
    °C maximum temperature
  • 4°C minimum temperature4
    °C minimum temperature
  • Cloudy with some rain
    cloudy with some rain
  • No hours of bright sunshine0
    hours of sunshine
  • UV (maximum) index 1 (Low)1
    UV index (Low)
  • 81% chance of some rain81
    % chance of some rain
  • 5-10 mm of rainfall expected<10
    mm of rainfall expected
  • No heat & humidity0
    no heat & humidity
  • Moderate breeze of 24 kph from the North-West24
    kph wind from NW

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Thunder Bay weather for Thursday 4th September 2025

Expect cloudy with sleet or snow in Thunder Bay, Ontario with a maximum temperature of 10°C, maximum UV of 2 (Low) and 2 hours of bright sunshine. There are 5-10 mm of sleet/snow expected with 65% chance of some sleet or snow and a moderate breeze of 20 kph from the north-west.

  • 10°C maximum temperature10
    °C maximum temperature
  • 3°C minimum temperature3
    °C minimum temperature
  • Cloudy with sleet or snow
    cloudy with sleet or snow
  • 2 hours of bright sunshine2
    hours of sunshine
  • UV (maximum) index 2 (Low)2
    UV index (Low)
  • 65% chance of some sleet or snow65
    % chance of some sleet or snow
  • 5-10 mm of sleet/snow expected<10
    mm of sleet/snow expected
  • No heat & humidity0
    no heat & humidity
  • Moderate breeze of 20 kph from the North-West20
    kph wind from NW

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Thunder Bay weather for Friday 5th September 2025

Expect mostly cloudy with rain in Thunder Bay, Ontario with a maximum temperature of 12°C, maximum UV of 2 (Low) and 2 hours of bright sunshine. There are 5-10 mm of rainfall expected with 44% chance of some rain and a moderate breeze of 25 kph from the north-west.

  • 12°C maximum temperature12
    °C maximum temperature
  • 4°C minimum temperature4
    °C minimum temperature
  • Mostly cloudy with rain
    mostly cloudy with rain
  • 2 hours of bright sunshine2
    hours of sunshine
  • UV (maximum) index 2 (Low)2
    UV index (Low)
  • 44% chance of some rain44
    % chance of some rain
  • 5-10 mm of rainfall expected<10
    mm of rainfall expected
  • 12°C wind chill12
    °C wind chill
  • Moderate breeze of 25 kph from the North-West25
    kph wind from NW

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Thunder Bay weather for Saturday 6th September 2025

Expect broken clouds in Thunder Bay, Ontario with a maximum temperature of 14°C, maximum UV of 2 (Low) and 4 hours of bright sunshine. There are 0 mm of rainfall expected and a moderate breeze of 21 kph from the north-west.

  • 14°C maximum temperature14
    °C maximum temperature
  • 5°C minimum temperature5
    °C minimum temperature
  • Broken clouds
    broken clouds
  • 4 hours of bright sunshine4
    hours of sunshine
  • UV (maximum) index 2 (Low)2
    UV index (Low)
  • 0 mm of rainfall expected0
    mm of rainfall expected
  • 14°C wind chill14
    °C wind chill
  • Moderate breeze of 21 kph from the North-West21
    kph wind from NW

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

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