Boulder usually has more than 300 sunny days a year.
Spring and fall are usually very nice if not perfect weather in boulder near perfect nice cool sunny days with a fresh mountain breeze.
In the summer it can get hot in the middle of the day it’s a good time of year to hang out by the creeks reservoirs of take trips up into the mountains. In the mountains up near the continental dive is usually around 15-20 degrees cooler then down in Boulder. On hot days it is also nice to take trip up to a glacier and go play in the snow in the middle of summer.
Winters are mild in boulder the coldest months are usually December and January but even in the middle of winter it is not unusual to get some nice days were it warms up to light jacket weather in the afternoon. Over all Boulder has a very mild winter for a place in the Rocky Mountain region.
The average yearly snowfall in Boulder is 83 inches. When it snows it will usually melt in a few days but there are times when an artic front can linger and keep it below freezing for a couple of weeks.
Boulder is about 20 miles east of the continental divide so much of the snow run off turns to many creeks that run trough boulder county.