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July Weather in Thunder Bay, Canada

Last updated: June 18, 2025

In July, the average temperature in Thunder Bay, Canada hovers around 19°C (66°F). Expect a minimum of 9°C (48°F) and a maximum soaring up to 31°C (89°F). The region experiences approximately 82 mm (3.2 in) of precipitation over 10 days, coupled with an average humidity of 70%. Plan accordingly to enjoy the best of what this beautiful place has to offer!

July Temperature in Thunder Bay

In July in Thunder Bay, the average temperature is 19°C (66°F), with maximums reaching 31°C (89°F) and minimums dipping as low as 9°C (48°F). This pleasant weather makes it an ideal time for traveling, allowing for a variety of outdoor activities and exploration.

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

The chart illustrates July 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, July typically has an average temperature of 19°C (66°F), with highs reaching up to 31°C (89°F) and lows dropping to around 9°C (48°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.

July Precipitation in Thunder Bay

In Thunder Bay in July, the total precipitation amount is 82 mm (3.2 in) observed over a span of 10 days.

July Precipitation Trends in Thunder Bay

The chart displays monthly precipitation patterns in Thunder Bay, with values for each month alongside July’s data, which is highlighted for easy comparison. It shows the amount of precipitation, providing insights into how July’s conditions compare to those of other months. In Thunder Bay, July typically receives around 82 mm (3.2 inches) of precipitation spread over approximately 10 days.
JanFebMarAprMayJunJulAugSepOctNovDec303531585258827798875255
Data source: Precipitation data for July generated using information from the Copernicus Climate Change Service.
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July Humidity in Thunder Bay

In Thunder Bay in July humidity is 70%. With an average temperature of 19°C (66°F), this humidity feels like a warm blanket enveloping you, making travel a bit sticky and prompting frequent breaks for water as you explore the sights.

July Average Humidity in Thunder Bay

This chart illustrates the average monthly humidity levels in Thunder Bay, with July’s data highlighted for easy comparison. It shows the fluctuation in humidity throughout the year, helping you understand how conditions vary by season. In July, average humidity in Thunder Bay is approximately 70%, 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 July generated using information from the Copernicus Climate Change Service.

July UV Index in Thunder Bay

In Thunder Bay in July, the maximum UV index is 8, which corresponds to a very high Exposure Category. This means that the time to burn is only 15 minutes. For more detailed information, you can refer to the Hourly UV Index in Thunder Bay.

Maximum UV Index Levels in Thunder Bay for July

The chart shows the monthly maximum UV Index (UVI) for Thunder Bay in July, 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 July, the maximum UV index in Thunder Bay typically reaches 8, which falls under the very high exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec235789887421
Data source: Thunder Bay July 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 July 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 July’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 July’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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