Trois Rivieres, Canada offers 1 beach perfect for sunbathing, surfing, swimming, and more. Trois Rivieres is known for the Forges du Saint-Maurice National Historic Site and the Borealis museum. The best time to visit Trois Rivieres, Canada, is from June to August, when the average air temperature is around 68°F (20°C) and the water temperature in the St. Lawrence River is approximately 64°F (18°C). Sandee provides detailed maps, photos, and reviews from fellow beachgoers to help you Choose Your Beach™ and plan your perfect beach vacation!