The best time to go to Baie Sainte-Catherine is during the summer months, from June to September, for prime whale watching and pleasant weather.During this period, the St. Lawrence River is bustling with marine life, offering the best chance to spot various whale species. The weather is generally warm and comfortable, great for boat tours, kayaking, or exploring the surrounding natural parks. Days are long, allowing for extended outdoor activities and scenic drives along the coast.For those interested in seeing beluga whales, July and August are particularly good months as they are often more visible in the Saguenay-St. Lawrence Marine Park. The warmer water temperatures also make other activities like hiking in the nearby fjord national park more enjoyable.While the summer is the most popular, early autumn, particularly September, offers a quieter experience with beautiful fall foliage and still good opportunities for whale watching, especially for fin and humpback whales before they migrate south.