Mid-November through mid-April is the best time to visit the central and eastern North Island. The weather is generally balmy, and apart from Christmas Day, New Year's Day, and Easter, everything is open. This is also the season for vineyard festivals, so keep an eye on the local calendars. Try to avoid the school holidays (from early December to late January), when the roads and hotels get clogged with Kiwi vacationers. If you'd like to see the gannet colony at Cape Kidnappers, you'll need to get out there between October and March, when the birds are nesting and raising their young.
Hawke's Bay and Gisborne can be remarkably mild in winter, but Rotorua and Taupo can get very cold, particularly when a southerly wind whips across the snowfields. It's not unusual for the Desert Road -- the stretch of State Highway 1 between Waiouru and Turangi -- to be closed by snow for short periods. Of course if you want to do some skiing, August is the month to hit the slopes of Tongariro National Park, though the first major snows can fall as early as late June.
