Denver is situated on the high plains at the base of the Rocky Mountains and has a mild, semi-arid climate all year long. Historically, no day in Denver is the same:
Wear layers (days may be warm, but nights tend to get chilly)
Be prepared for weather changing often and quickly
Expect temperatures in the mountains to be lower than in the city
Denver has four distinct seasons. Fall and springtime bring the most weather variety and conditions can vary greatly. During the winter the snow and extreme cold stays mostly in the mountains. Denver snowstorms are normally short-lived and snow melts quickly. Summer days are dry with temperatures usually in the 80s and 90s and summer nights are cool and comfortable.
Denver is best known for its 300 days of sunshine and low humidity, providing an ideal climate for year-round activities.
Denver is situated at a high altitude of 5,280 feet (one mile high) above sea level. Visitors from lower elevations often underestimate the effects of altitude on their health and physical abilities. With high altitude living, the body gradually acclimates to the lower air pressure and decreased oxygen. Until acclimation occurs, high altitude living can give rise to a variety of unpleasant symptoms characteristic of altitude sickness.
The symptoms of altitude sickness include nausea, lightheadedness, dizziness, headache, swelling in the feet, fatigue, sleep problems and breathing difficulties. To bypass these symptoms drink water to avoid dehydration and consume less alcohol and caffeine. Also, avoid heavy exercise initially to allow the body time to make the physiologic changes needed to function properly.
High altitude living and vacationing puts additional stress on the body and should always be approached with caution.