Understand
"Park" in this case is a term that means a valley or meadow. Estes Park is named after an early settler, Joel Estes, who attempted to make a living by farming. Because of the short growing season it never really worked out. Since the mid-1800's the main business of Estes Park has been tourism. The clientele ranges from hard-core backcountry types to tour-buses full of drive through sightseers. The main draw is the scenery, which is awesome.
Year-round population is approximately 6,000 people, adding the surroundings it may be 10,000. In the peak of tourist season that probably triples. The best time to visit for outdoor activities is July through September. Everyone else thinks so too, so it can get kind of crowded. The heaviest traffic is probably in August. The family/kids crowd thins out after Labor Day.
Winter is a charming time of the year as well, since it is an excellent time to go snow shoeing and cross country skiing. Winter also provides greater opportunities to enjoy the tranquility of the Rocky Mountains as there are fewer tourists.
Winter weather is warmer than most mountain towns. But summer is also short. Summer temps peak in the low 90'sF in town, much cooler as elevation increases. If you plan on spending any time out of your car up on Trail Ridge Road take a jacket. Estes is in a dry zone, getting maybe 13-15 inches of moisture a year. During the summer the regular weather pattern is clear mornings with a buildup of clouds at midday and sometimes a short rain shower.
Elevation in town is 7,522 feet above sea level. Some people experience discomforts due to altitude.