Weather is probably a major factor when you plan your trip to Vana-Kaiu, and keep in mind that cheaper options are usually available when the weather isn't as good. The hottest months are usually July and August with an average temp of 60°F, while the coldest months are January and February with an average of 27°F. The snowiest months in Vana-Kaiu are November, December, January, and February, with each month seeing an average of 9 inches of snowfall.