The best time to go to Thunder Bay is during the summer months, from June to August, or in the early autumn, specifically September.Summer offers the warmest weather, with average daily temperatures often reaching the low to mid-20s Celsius. This period is ideal for enjoying the outdoors, including activities on Lake Superior and exploring the many hiking trails in the surrounding provincial parks. You'll find all attractions, shops, and restaurants operating on their full summer schedules, making it a convenient time for sightseeing and dining out.September provides a lovely transition, with cooler, crisp air and the beginning of the autumn colours. Temperatures typically range from 10 to 18 degrees Celsius. This is a fantastic time for couples who enjoy scenic drives and hiking, as the fall foliage along the North Shore of Lake Superior is particularly stunning. Many outdoor activities are still available, often with fewer crowds than in peak summer.