Weather in Thunder Bay in July

A good month. July is a solid month to be in Thunder Bay. Highs average 24.7 °C, lows 13.4 °C, and rain falls on 14 days — nothing in the month is working against you.

July ranks 2 of 12 in Thunder Bay. Only August scores clearly higher, and the difference is small enough to be settled by price rather than weather.

This is persistent light rain rather than storms: 14 wet days but only 2 heavy ones. It rarely cancels anything outright, and it rarely fully clears either. A jacket beats an umbrella. Nothing specialised needed — this is the month you pack for the trip rather than for the weather.

What the averages hide

The averages here are honest — no hidden extremes worth planning around. Across the twenty years measured, the hottest July day reached 34.5 °C and the coldest night fell to 6.4 °C, and the wettest single day dropped 32 mm — roughly 43% of the month's rain in one day.

July is statistically steady but not small: the year-to-year variation is modest in relative terms, yet the wettest July on record still delivered 116 mm against 43 mm in the driest. In a month this wet, even a tame spread is a lot of rain in absolute terms — the 75 mm average is a reasonable planning figure, not a promise.

Wind is light at 1.6 km/h, so the temperature on the page is close to the temperature on your skin, and humidity runs at 75%, high enough to notice on the warm days without dominating them.

How July sits in the year

Temperatures hold steady either side: 20.9 °C in June, 24.7 here, 24.4 in August. Nothing about the timing within the month matters much.

Daylight in July

July is at or near the longest days of Thunder Bay's year: 15.7 hours of daylight, losing 0.9 hours across the month. Evenings are the real gain — dinner outdoors still happens in full light.

An inland climate

Thunder Bay has no sea to moderate it, and it shows: 42 °C separates the hottest afternoon of the year from the coldest night. That is a genuinely continental range, and it means summer and winter here are barely the same place.

How busy it gets

Peak season. Expect the highest prices of the year and to be booking well ahead.

Crowd levels are estimated from climate desirability and school-holiday calendars, not from visitor numbers.

July in Thunder Bay versus nearby

If Thunder Bay is one option among several, the nearby comparison is worth making. Minneapolis is close enough to be a coin toss — 3.8 °C warmer, 3 days less rain. Milwaukee is close enough to be a coin toss — 3.3 °C warmer, 2 days less rain.

So: July is effectively as good as it gets here — 4 points behind August, which is inside the margin where the weather stops being the deciding factor and price starts being it.

Every month in Thunder Bay

See all twelve months in Thunder Bay, or where else to go in July.