For most travellers, the best time to visit Boston, Sweden is during the summer months, from June to August, or in the shoulder seasons of May and September.Summer offers the warmest weather and longest daylight hours, making it ideal for exploring the city's outdoor attractions and enjoying boat trips in the archipelago. Temperatures are generally pleasant, ranging from 18°C to 22°C. This is a popular time, so expect more people and higher prices for accommodation and flights.May and September provide a lovely balance of good weather and fewer crowds. In May, the city comes alive with blooming flowers, and temperatures are mild, around 15°C. September brings crisp air, beautiful autumn colours, and temperatures similar to May, making it great for walking tours and enjoying the city's parks.