Rangitoto Island in September

October through April is peak season when ferries run daily and the pohutukawa trees bloom their brilliant red flowers (December-January is spectacular). But here's the insider tip: May and September can be perfect if you don't mind weekend-only ferry service. The weather is still mild, crowds are minimal, and you'll have the island largely to yourself. Summer gets hot on those black volcanic slopes — temperatures can feel 5-10 degrees warmer than Auckland city due to the dark rock absorbing heat. Early morning ferries (around 9am) are smart in summer to avoid the worst heat on the summit climb. Winter visits are possible but limited to weekends only, and the weather can be unpredictable. The island looks dramatically different in winter — more moody and mysterious, but you'll need proper rain gear. Avoid visiting during Auckland's westerly wind storms; the ferry service gets cancelled and the exposed island can be unpleasant.