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March Weather in Thunder Bay, Canada

Last updated: June 18, 2025

In Thunder Bay, Canada, the average temperature in March hovers around -5°C (23°F). Temperatures can dip as low as -26°C (-14°F), while reaching a maximum of 10°C (51°F). Prepare for some damp days with an average precipitation of 31 mm (1.2 in) spread over 5 days, and brace yourself for high humidity levels at a notable 92%.

March Temperature in Thunder Bay

In March in Thunder Bay, the average temperature is -5°C (23°F). The maximum can reach 10°C (51°F), and the minimum can be as low as -26°C (-14°F). Be sure to pack warm clothing and prepare for a range of winter weather conditions if you're planning to travel during this time.

March Weather in Thunder Bay: Daily Temperature Highs, Lows, and Averages

The chart illustrates March temperature patterns in Thunder Bay, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Thunder Bay, March typically has an average temperature of -5°C (23°F), with highs reaching up to 10°C (51°F) and lows dropping to around -26°C (-14°F).
JanFebMarAprMayJunJulAugSepOctNovDec9923334758666355432716
Data source: Temperature data for Thunder Bay generated using information from the Copernicus Climate Change Service.
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The average of daily temperatures (24 hours) calculated across all days in the month.

March Precipitation in Thunder Bay

In Thunder Bay in March, the precipitation amount is 31 mm (1.2 in) spread over 5 days.

March Precipitation Trends in Thunder Bay

The chart displays monthly precipitation patterns in Thunder Bay, with values for each month alongside March’s data, which is highlighted for easy comparison. It shows the amount of precipitation, providing insights into how March’s conditions compare to those of other months. In Thunder Bay, March typically receives around 31 mm (1.2 inches) of precipitation spread over approximately 5 days.
JanFebMarAprMayJunJulAugSepOctNovDec303531585258827798875255
Data source: Precipitation data for March generated using information from the Copernicus Climate Change Service.
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March Humidity in Thunder Bay

In Thunder Bay in March humidity is 92%. With an average temperature of -5°C (23°F), this humidity feels like an intense chill that penetrates layers of clothing, making outdoor travel uncomfortable and breath crisp, often leaving one feeling damp and cold despite the low temperatures.

March Average Humidity in Thunder Bay

This chart illustrates the average monthly humidity levels in Thunder Bay, with March’s data highlighted for easy comparison. It shows the fluctuation in humidity throughout the year, helping you understand how conditions vary by season. In March, average humidity in Thunder Bay is approximately 92%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec95%94%92%90%79%71%70%72%76%82%87%94%
Data source: Humidity data for March generated using information from the Copernicus Climate Change Service.

March UV Index in Thunder Bay

In Thunder Bay in March, the maximum UV index reaches 5, which corresponds to a moderate Exposure Category. Under these conditions, the estimated time to burn is approximately 30 minutes. For more details, you can check the Hourly UV Index in Thunder Bay.

Maximum UV Index Levels in Thunder Bay for March

The chart shows the monthly maximum UV Index (UVI) for Thunder Bay in March, representing the highest UV radiation level. The UVI measures the intensity of ultraviolet radiation from the sun, indicating the potential risk of sunburn and UV-related health issues. In March, the maximum UV index in Thunder Bay typically reaches 5, which falls under the moderate exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec235789887421
Data source: Thunder Bay March UVI data generated using information from the Copernicus Climate Change Service.

UV Risk Categories

  •  Extreme (11+): Avoid the sun, stay in shade.
  •  Very High (8-10): Limit sun exposure.
  •  High (6-7): Use SPF 30+ and protective clothing.
  •  Moderate (3-5): Midday shade recommended.
  •  Low (0-2): No protection needed.

How March Weather in Thunder Bay Compares to Other Months

Weather in Thunder Bay varies notably across the year, with each month offering distinct climate conditions. This page compares March’s weather to other months in Thunder Bay, focusing on differences in temperature, rainfall, humidity, and UV levels.

This table compares monthly weather conditions in Thunder Bay, showing how March’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
 TemperaturePrecipitationHumidityUV
January Weather-13°C (9°F)30 mm (1.2 inches)95%low
February Weather-13°C (9°F)35 mm (1.4 inches)94%moderate
March Weather-5°C (23°F)31 mm (1.2 inches)92%moderate
April Weather1°C (33°F)58 mm (2.3 inches)90%high
May Weather8°C (47°F)52 mm (2.0 inches)78%very high
June Weather14°C (58°F)58 mm (2.3 inches)71%very high
July Weather19°C (66°F)82 mm (3.2 inches)70%very high
August Weather17°C (63°F)77 mm (3.0 inches)72%very high
September Weather13°C (55°F)98 mm (3.9 inches)76%high
October Weather6°C (43°F)87 mm (3.4 inches)82%moderate
November Weather-3°C (27°F)51 mm (2.0 inches)87%low
December Weather-9°C (16°F)55 mm (2.2 inches)94%low

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