The lake is at its best from late May through September. July and August are the busiest — the foreshore fills with swimmers and the trailheads with hikers — but it still feels far less crowded than Lake Bled up the road. September and the first half of October bring quieter trails, clear weather and the start of the autumn colours; this is many people's favourite time. May and early June give you snowmelt-fat waterfalls and a chance of wildflowers in the high meadows.
Winter (December to early April) brings reliable snow up high, where the Vogel ski area runs, but the lake itself often only freezes in short cold spells. Roads stay open year-round; chains are sometimes required on the climb up to Bohinjska Bistrica after heavy snow.