Although weather is just one factor, it can really affect your travel plans, especially if you're planning an extended stay in Greenhorn. The hottest months are usually July and August, with an average temperature of 19°C, while the coldest months are December and January, with an average of -1°C. The snowiest months in Greenhorn are January, February, March and April, with each month seeing an average of 22 cm of snowfall.