Plitvice Lakes in January

May through September offers the warmest weather and fullest waterfalls from spring snowmelt. July and August bring peak crowds but also the most reliable sunshine. September hits the sweet spot — fewer tourists, still-warm days, and early fall colors starting to show. Spring can be muddy and unpredictable, while winter closes some trails entirely. Avoid Croatian school holidays if possible, and weekdays always beat weekends. Rain actually makes the waterfalls more dramatic, so don't let cloudy skies scare you off.