The best time to visit Sejny is during the warmer months, specifically from late spring to early autumn (May to September), when the weather is most pleasant for outdoor activities and exploring the region.During these months, the temperatures are comfortable, ranging from mild to warm, making it ideal for enjoying the natural beauty of the Augustów Primeval Forest and the numerous lakes in the area. You'll find the days are longer, offering more daylight hours for sightseeing and recreation.For those interested in water sports, fishing, or hiking, July and August offer the warmest temperatures and the most sunshine. This is also when local events and festivals are more likely to take place, providing a glimpse into the regional culture.If you prefer fewer crowds and slightly cooler, yet still pleasant, weather, May, June, and September are excellent choices.