January
National Western Stock Show and Rodeo - One of the biggest rodeo events in the United States, this event features rodeos, Western-themed entertainment and plenty of 10-gallon hats.

February
Denver Restaurant Week - This seven-day celebration gives you a chance to sample a variety of delicious Denver food. Restaurants offer multi-course dinners at fixed prices.

March
Saint Patrick's Day Parade - The U.S.'s second largest St. Patrick's Day Parade. Festivities are embellished with pub venue excitement!

April
Doors Open Denver - Historical buildings and structures that are usually closed to the public open their doors. Tour more than 70 sites and buildings on your own or take a tour led by an expert.

May
Downtown Denver Arts Festival - Held at Denver Pavilions on Memorial Day Weekend, more than 125 artists from around Colorado exhibit and sell their work at this event. Take the chance to meet the artists at this free festival.

June
Bethesda Dutch Festival - For a true taste of Dutch custom and tradition, this is one event you won't want to pass over! The festival is packed with delectable eating enjoyment and fun for all ages!

Colorado Renaissance Festival - Held annually from June through July, the festival boasts awesome reenactments of knights, Renaissance nobility and crafts.

Juneteenth - Commemorating the emancipation of the slaves in Texas, this annual June 19th festival is packed with festivities.

July
Cherry Creek Arts Festival - Held annually on the 4th of July weekend. Delighting the true bohemian, this nationally renowned festival features an eclectic art display.

August
Colorado State Fair - This large celebration features rides, games, music, showcases and a rodeo. Other features include live entertainment and children's activities.

September
Great American Beer Festival - Taste more than 1,500 beers from around the world.

November
Winterfest - Held at Larimer Square, this event features seasonal decorations and celebrations. Holiday music and food are also featured.

December
Georgetown Christmas Market - This German-style Christmas market features many booths and gifts. Holiday music, food and activities are also featured.

Sources:
(http://www.10bestcityguides.com/)

(http://www.denver.location-guides.com/denver_festivals.html)