Weather is probably a major factor when you plan your trip to Vana-Kaiu, but bear 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 temperature of 16°C, while the coldest months are January and February, with an average of -3°C. The snowiest months in Vana-Kaiu are November, December, January and February, with each month seeing an average of 23 cm of snowfall.