Weather is probably a major factor when you plan your trip to Stevenson, but bear in mind that cheaper options are usually available when the weather isn't as good. The hottest months are usually August and July, with an average temperature of 17°C, while the coldest months are December and January, with an average of 2°C. The rainiest months in Stevenson are December, January, November and March, with each month seeing an average of 319 mm of rainfall.