The summer season for visitors and tourist attractions typically starts in May and runs through September, with some operations opening later and closing a little earlier, depending on location – check the state tourism websites for more specific information on opening and closing dates.
The winter season typically runs from November through March. Please check with the relevant resort or State websites for specific operating dates and weather conditions.
In a word, the weather in the Rocky Mountains is unpredictable. Temperatures are at best extreme, but you can expect temperatures to usually average in the high 60s to low 70s degrees Fahrenheit (20 to 22 degrees Celsius) between early June and September. Below we’ve outlined general temperatures throughout the year.
Moderate temperatures in the lower elevations. Ski areas open through March.
Days: Sunny and hot, with temperatures reaching 80s and low 90s F (27 to 32 degrees C).
Nights: 25-30 degrees F (-1 to 4 degrees C). Higher elevations, and in places like Yellowstone National Park and Glacier National Park, be prepared for a sudden snow or rain shower even in mid-summer. The higher the elevation, the colder it gets.
Crisp daytime temperatures. Frosty nights. Some ski resorts open in November. Weather can be unpredictable in the fall. The days may be very nice, maybe even warm, however, the evenings cool off quite a bit. It is possible to get snow and/or rain. We recommend wearing layers and it is highly recommended that you bring a heavy coat, hat, and gloves and warm shoes and boots. Sunscreen, sunglasses, and lip balm are also useful items to have on hand.
Temperatures can average below freezing.