Summer (June to August) is the main season. The town fills with Polish and German holiday-makers, the marinas are busy, and all rental and tour operators are open. July and August see the heaviest crowds and highest prices; June and September are noticeably quieter while still warm enough for sailing and kayaking.
Winter has its own appeal for those who know about it. The lakes freeze most years between January and mid-March, and ice sailing is a serious sport here — the town has hosted ice sailing events since the 19th century. The kite-skating and ice-yacht community gathers on Lake Tałty when conditions allow. Outside of summer and mid-winter, most hotels and restaurants close: spring and autumn are difficult seasons in Mikołajki.
The Rally of Poland, headquartered in Mikołajki, typically runs in late June or early July and brings significant noise and crowds to the surrounding forest roads.