Planning for the weather is a good way to make your trip to Mount Aspiring National Park relaxing and enjoyable, especially when you're splurging. The hottest months are usually February and January, with an average temperature of 14°C, while the coldest months are July and August, with an average of 7°C. The rainiest months in Mount Aspiring National Park are May, December, January and October, with each month seeing an average of 444 mm of rainfall.