The highest day temperature in July 2026 was 109°F. The lowest night temperature was 51°F. The average values for day and night temperatures during July were 85.2°F и 61.3°F respectivly.

The average sea surface temperature in July 2026 for Thunder Bay was 51.8°F. The maximum and minimum values were 44.2°F and 61.2°F respectively.

Most of the days in July are sunny but you can also expect cloudy and gloomy days.

Precipitation total in July for Thunder Bay is 0.8 in. It makes july one of the most rainy months of the year.

The average wind speed in July is 5.8 mph. It makes July the most windless month of the year for Thunder Bay.

We are using day length and cloud cover information for each day of the month to calculate averages for this chart. Average sunny hours for Thunder Bay in July is 9.9 hours.