Fiordland National Park in January

Summer means crowds but also the most reliable weather. December through February sees 14-hour daylight and temperatures that might actually hit 20°C on a good day. But here's the catch — this is also when every tourist in New Zealand descends on Fiordland. Expect full huts and packed viewpoints. March and April are the sweet spot. The crowds thin out, autumn colors paint the beech forests gold, and you get more stable weather than winter. I've had my best Fiordland experiences in late March when morning frost gives way to crystal-clear afternoons. Winter hiking from May to August requires serious experience. Days are short, snow closes high passes, and some tracks shut down entirely. But if you can handle it, winter Fiordland is otherworldly — think frozen waterfalls and snow-capped peaks reflected in perfectly still lakes. Spring from September to November is unpredictable. One day brings sunshine and wildflowers, the next dumps a meter of snow on the passes. Only attempt this season if you're comfortable with rapid weather changes and potential track closures.