Weather is probably a major factor when you plan your trip to Mariazell, 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 0°C. The rainiest months in Mariazell are May, July, June and August, with each month seeing an average of 177 mm of rainfall.