Boulder, Colorado

Boulder population, 2020 to 2024

Boulder lost 1,615 residents from July 2020 to July 2024, a change of -1.5%. In the latest year it moved by +169. Among 79 Colorado places of 5,000 or more, that growth ranks 65th; the median place changed by +3.0%. The median place of 5,000+ in Colorado has 14,061 people, so Boulder is 7.6 times that size.

Boulder covers 26.88 square miles of land and 1.05 of water, for 3,973 people per square mile of land. The median Colorado place of 5,000+ has 1,848, so Boulder is denser than the typical town.

What county Boulder is in

All of Boulder's residents live in Boulder County, which had 330,262 residents in 2024. Boulder holds 32.3% of the county's population. The shaded shape is on the map above; dots mark the eight nearest places.

ZIP codes in Boulder

6 ZIP Code Tabulation Areas (ZCTAs) overlap Boulder by at least 10% of the ZCTA's or the city's land: 80301, 80302, 80303, 80304, 80305, 80310. ZCTAs are Census approximations of USPS ZIP code delivery areas. The list comes from the 2020 ZCTA to place relationship file, so a city that annexed land after 2020 may reach into ZIP codes not listed here.

Where Boulder is

The Census internal point of Boulder is at 40.024400, -105.251300. Denver, the capital, is 24.3 miles SE in a straight line. The nearest larger place is Westminster, CO (115,302 people), 14.2 miles away. The ground at the internal point is about 1,605 m (5,266 ft) above sea level.

Daylight in Boulder

At 40.02° N, Boulder gets about 15 h 01 min of daylight around the June solstice and 9 h 20 min around the December solstice, a swing of 5 h 42 min. Figures are sunrise to sunset from the SunCalc model for June 21 and December 21, 2026. Month-by-month sunrise and sunset times are on the Boulder daylight page.

Places near Boulder

The eight nearest incorporated places of 1,000+ in Colorado, measured between internal points. The closest is Louisville, 6.9 miles away, with 20,811 people.