Boulder Colorado Weather

by Jim Harrington

First day of summer vacation and very occasionally over a foot of snow can fall in the Boulder foothills. Even in the heat of July an afternoon thunderstorm can turn into a hail storm blanketing town and trails with marble sized snowballs. For an hour even Boulder in the northern hemisphere during the middle of summer may really feel like the middle of winter. Weather changes like this, even for an hour, can be a little bit scary. People are advised to be prepared when they hike the high country just outside Boulder’s backyard.  Wait 15 minutes or walk a mile and the weather can change but not always this drastically but sometimes.
Fortunately you also have to be prepared for drastic weather changes in winter.  But it is a change to really be enjoyed. Sun shining days are not far away even in the midst of winters grip. In Boulder you might grip ski poles in the morning, golf clubs and bike handlebars in the afternoon. Bike paths are plowed well before many roads.  Enjoy it all. It still snows in winter it’s just the sun is out in a day or two to melt it away. It is rare to see old snow banks in town. When it snows Boulder likes it fresh, beautiful and gone in a few days. Locals love to visit the accumulation of snow in the high country for some of the best skiing in the world they just don’t want the snow to stay around town too long.
Colorado tourism will tell you Colorado has 300 days of sunshine out of the year. Since the National Weather service is headquartered here in Boulder it’s only fair to set the record straight and acknowledge that is not 100% accurate. Sometimes the sun just peeks out for a couple hours a day. Do you measure the day sunny if the sun is out for four hours or does it have to be sunny all day?  Boulderites just feel like they are basking in the sun year round. For a climate with all four seasons intact Boulder has a lot of sunshine in each. If Boulder locals do not get to see the sun, not even a peek, for even a couple days they have a major depression you expect from people who have not seen the sun for weeks. It is not scientific but it does show Boulderites get regular Vitamin D sunshine all year. In springtime people will have both their winter boots and their sandals ready to wear on any particular day.  Both are needed.
Boulder has pleasant year-round weather and has a high-desert climate at an altitude of 5,430 feet or a bit over a mile high above sea level. This elevation ensures a mild climate with very little humidity. Locals will start commenting on the humidity if it rises above 30%. The warmest month is in July with an average daytime temperature of 87 degrees Fahrenheit. January is the coldest month in Boulder, with an average daytime high of 45 degrees.
It can get windy in Boulder. The windmills you can see out of town, on the horizons ridge, near the mouth of a canyon are not for power generation but for testing. There is just too much erratic wind at the top of that hill for good wind energy production. If a windmill can function during the high winds coming off the continental divide and gushing through the canyons then they can function well on the plains where the winds are gently more consistent. How awful is it that hurricane force winds of 100 mph or more sometimes come down from the high country into Boulder? Really it’s a blessing called a Chinook Wind. The word Chinook means “Snow Eater” because Native Americans had noticed that when a warm wind blew down the mountains, the snow would disappear. The winter winds warm up on their descent and create a warmer climate in Boulder Valley below where the city resides at the base of the foothills. There are no homes where the windmills are being tested outside the valley. The winds provide cooling in the summertime with the fragrance of a mountain forest throughout the cosmopolitan city. The winds in Boulder are generally gentle but sometimes they can be very gusty for brief periods of time.
When it snows in May or the wind blows hard that is when Boulder weather makes the national news. That’s ok. A secret we want to share with only a few is that Boulder weather is pretty nice on all the other days of the year.  Come to Boulder and we think you will enjoy playing outside!