Thunder Bay weather live forecast

Today's maximum temperature in Thunder Bay is expected to be 20°C. Select a day from the live weather forecast for Thunder Bay, Ontario, Canada for more weather parameters.

5-day weather forecast updated at 04:00 on Friday 4th September 2026 GMT

More about Thunder Bay

Thunder Bay by month

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Recommended for Ontario

Crystal Ski: Top ski deals to Canada

  • Save on skiing holidays to Canada in winter 2025/2026
  • Book early with Crystal Ski for the best deals
  • Filter by promotional offers, duration, board basis & more
Go to Crystal Ski deal >>

View all Crystal Ski offers

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 Friday 4th September 2026

Expect mostly cloudy with rain in Thunder Bay, Ontario with a maximum temperature of 20°C, maximum UV of 3 (Moderate) and 2 hours of bright sunshine. There are 5-10 mm of rainfall expected with 28% chance of some rain and a gentle breeze of 18 kph from the east.

  • 20°C maximum temperature20
    °C maximum temperature
  • 14°C minimum temperature14
    °C minimum temperature
  • Mostly cloudy with rain
    mostly cloudy with rain
  • 2 hours of bright sunshine2
    hours of sunshine
  • UV (maximum) index 3 (Moderate)3
    UV index (Moderate)
  • 28% chance of some rain28
    % chance of some rain
  • 5-10 mm of rainfall expected<10
    mm of rainfall expected
  • 20°C wind chill20
    °C wind chill
  • Gentle breeze of 18 kph from the East18
    kph wind from E

Back to top

Thunder Bay weather for Saturday 5th September 2026

Expect broken clouds in Thunder Bay, Ontario with a maximum temperature of 22°C, maximum UV of 6 (High) and 3 hours of bright sunshine. There are 0 mm of rainfall expected and a light breeze of 10 kph from the north-east.

  • 22°C maximum temperature22
    °C maximum temperature
  • 15°C minimum temperature15
    °C minimum temperature
  • Broken clouds
    broken clouds
  • 3 hours of bright sunshine3
    hours of sunshine
  • UV (maximum) index 6 (High)6
    UV index (High)
  • 0 mm of rainfall expected0
    mm of rainfall expected
  • No heat & humidity0
    no heat & humidity
  • Light breeze of 10 kph from the North-East10
    kph wind from NE

Back to top

Thunder Bay weather for Sunday 6th September 2026

Expect sunshine and showers in Thunder Bay, Ontario with a maximum temperature of 24°C, maximum UV of 6 (High) and 6 hours of bright sunshine. There are 0-2 mm of rainfall expected with 24% chance of some rain and a light breeze of 10 kph from the south-east.

  • 24°C maximum temperature24
    °C maximum temperature
  • 13°C minimum temperature13
    °C minimum temperature
  • Sunshine and showers
    sunshine and showers
  • 6 hours of bright sunshine6
    hours of sunshine
  • UV (maximum) index 6 (High)6
    UV index (High)
  • 24% chance of some rain24
    % chance of some rain
  • 0-2 mm of rainfall expected<2
    mm of rainfall expected
  • 24°C wind chill24
    °C wind chill
  • Light breeze of 10 kph from the South-East10
    kph wind from SE

Back to top

Thunder Bay weather for Monday 7th September 2026

Expect isolated thunderstorms in Thunder Bay, Ontario with a maximum temperature of 20°C, maximum UV of 4 (Moderate) and no hours of bright sunshine. There are 5-10 mm of rainfall expected with 62% chance of some rain and a moderate breeze of 22 kph from the east.

  • 20°C maximum temperature20
    °C maximum temperature
  • 13°C minimum temperature13
    °C minimum temperature
  • Isolated thunderstorms
    isolated thunderstorms
  • No hours of bright sunshine0
    hours of sunshine
  • UV (maximum) index 4 (Moderate)4
    UV index (Moderate)
  • 62% chance of some rain62
    % chance of some rain
  • 5-10 mm of rainfall expected<10
    mm of rainfall expected
  • 20°C wind chill20
    °C wind chill
  • Moderate breeze of 22 kph from the East22
    kph wind from E

Back to top

Thunder Bay weather for Tuesday 8th September 2026

Expect isolated thunderstorms in Thunder Bay, Ontario with a maximum temperature of 20°C, maximum UV of 1 (Low) and 1 hour of bright sunshine. There are 10-20 mm of rainfall expected with 86% chance of some rain and a moderate breeze of 24 kph from the south-east.

  • 20°C maximum temperature20
    °C maximum temperature
  • 13°C minimum temperature13
    °C minimum temperature
  • Isolated thunderstorms
    isolated thunderstorms
  • 1 hour of bright sunshine1
    hour of sunshine
  • UV (maximum) index 1 (Low)1
    UV index (Low)
  • 86% chance of some rain86
    % chance of some rain
  • 10-20 mm of rainfall expected<20
    mm of rainfall expected
  • No heat & humidity0
    no heat & humidity
  • Moderate breeze of 24 kph from the South-East24
    kph wind from SE

Back to top

Air Canada: Top flight deals to Canada

  • Discover top Air Canada offers on flights to Canada
  • Browse lowest fares available or search by date
  • Book flights to Toronto, Vancouver, Calgary, Montreal & more
Go to Air Canada deal >>

View all Air Canada offers

More about Ontario

Related posts

Popular travel offers

Explore holiday destinations

More holidays

Save with latest deals & discounts

More deals

Airport parking

More parking

Airport lounges

More lounges

Top ^