The weather in Denver Colorado is generally mild, but can be unpredictable with the Rocky Mountains to the west and the High Plains to the east. There are four distinct seasons of Denver weather: The summers generally bring highs in the upper 80s to lower 90s with frequent afternoon showers which cool things back down. The Rocky Mountains due west, while receiving lots of snow themselves, often act as a shield keeping the winters fairly mild in town. Winter snow storms do occur but usually melt before nightfall. March is Denver's snowiest month. November comes in second.