Oudeschild works year-round, though the character shifts with the season. Summer (June–August) brings the most activity: the harbour is busiest, the museum fills up, herring stalls are open, and boat trips run regularly. Evenings are long and the light on the Waddenzee is beautiful. It can get crowded in July and August, when the whole island fills with Dutch holidaymakers.
Spring and autumn are arguably the best times. The crowds thin, the light turns golden, and the birdlife on the Waddenzee mudflats peaks — spring migration (April–May) and autumn migration (September–October) bring enormous numbers of wading birds and wildfowl. Museum Kaap Skil is open but quieter.
Winter is quiet and atmospheric. Some cafes reduce hours or close; the herring stalls disappear. But the harbour in a November sea-fog has a particular bleakness that is its own reward. The museum stays open through winter, making it a fine reason to visit even on a cold grey day.