Weather is probably a major factor when you plan your trip to Greeley, 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 22°C, while the coldest months are January and February, with an average of -1°C. The snowiest months in Greeley are January, March, December and October, with each month seeing an average of 20 cm of snowfall.