Planning for the weather is a good way to make your trip to Haast 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 Haast are May, December, January and October, with each month seeing an average of 444 mm of rainfall.