Centennial is a part of the Denver-Aurora-Lakewood, CO Metropolitan Statistical Area. Centennial is the tenth most populous municipality in the state of Colorado and its 2001 city incorporation was the largest in U.S. history. Centennial is ranked as the 15th-safest city in the country. The next time you need flowers in Centennial, CO, think of Arapahoe Floral. We have same day delivery.