September is generally considered the best month to spend a weekend in Dubrovnik. It offers the ideal balance of warm Mediterranean weather, swimmable sea temperatures, and significantly fewer crowds compared to the peak summer months. However, the ideal time depends on your travel preferences. If you want a lively atmosphere, hot weather, and bustling beach clubs, visit in July or August. If you prefer cooler weather for comfortable sightseeing around the historic Old Town, May or October are fantastic alternative options.