Sunrise and Sunset times in Boulder, United States 
Today:
 Sunrise: 07:07:03
|
 Sunset: 16:35:46
|
Day Length: 9h 28m 43s
Time zone: America/Denver, UTC -7 h.
Latitude: 40.0249, Longitude: -105.252
Boulder
Colorado, United States 
126 054 people
| Date | Sunrise | Solar Noon | Sunset | Day length |
|---|---|---|---|---|
| 2025-Dec-01, Monday | 07:04:09 | 11:50:13 | 16:36:17 | 9h 32m 8s |
| 2025-Dec-02, Tuesday | 07:05:08 | 11:50:36 | 16:36:04 | 9h 30m 56s |
| 2025-Dec-03, Wednesday | 07:06:06 | 11:51:00 | 16:35:54 | 9h 29m 48s |
| 2025-Dec-04, Thursday | 07:07:03 | 11:51:25 | 16:35:46 | 9h 28m 43s |
| 2025-Dec-05, Friday | 07:07:59 | 11:51:49 | 16:35:40 | 9h 27m 41s |
| 2025-Dec-06, Saturday | 07:08:53 | 11:52:15 | 16:35:36 | 9h 26m 43s |
| 2025-Dec-07, Sunday | 07:09:47 | 11:52:41 | 16:35:35 | 9h 25m 48s |
| 2025-Dec-08, Monday | 07:10:39 | 11:53:07 | 16:35:36 | 9h 24m 57s |
| 2025-Dec-09, Tuesday | 07:11:29 | 11:53:34 | 16:35:39 | 9h 24m 10s |
| 2025-Dec-10, Wednesday | 07:12:18 | 11:54:01 | 16:35:44 | 9h 23m 26s |
| 2025-Dec-11, Thursday | 07:13:06 | 11:54:29 | 16:35:52 | 9h 22m 46s |
| 2025-Dec-12, Friday | 07:13:52 | 11:54:57 | 16:36:02 | 9h 22m 10s |
| 2025-Dec-13, Saturday | 07:14:37 | 11:55:25 | 16:36:14 | 9h 21m 37s |
| 2025-Dec-14, Sunday | 07:15:20 | 11:55:54 | 16:36:28 | 9h 21m 8s |
| 2025-Dec-15, Monday | 07:16:01 | 11:56:23 | 16:36:44 | 9h 20m 43s |
| 2025-Dec-16, Tuesday | 07:16:41 | 11:56:52 | 16:37:03 | 9h 20m 22s |
| 2025-Dec-17, Wednesday | 07:17:19 | 11:57:21 | 16:37:24 | 9h 20m 5s |
| 2025-Dec-18, Thursday | 07:17:55 | 11:57:51 | 16:37:47 | 9h 19m 52s |
| 2025-Dec-19, Friday | 07:18:29 | 11:58:20 | 16:38:12 | 9h 19m 43s |
| 2025-Dec-20, Saturday | 07:19:01 | 11:58:50 | 16:38:39 | 9h 19m 38s |
| 2025-Dec-21, Sunday | 07:19:32 | 11:59:20 | 16:39:08 | 9h 19m 36s |
| 2025-Dec-22, Monday | 07:20:00 | 11:59:50 | 16:39:39 | 9h 19m 39s |
| 2025-Dec-23, Tuesday | 07:20:27 | 12:00:20 | 16:40:12 | 9h 19m 45s |
| 2025-Dec-24, Wednesday | 07:20:51 | 12:00:49 | 16:40:48 | 9h 19m 57s |
| 2025-Dec-25, Thursday | 07:21:14 | 12:01:19 | 16:41:25 | 9h 20m 11s |
| 2025-Dec-26, Friday | 07:21:34 | 12:01:49 | 16:42:03 | 9h 20m 29s |
| 2025-Dec-27, Saturday | 07:21:53 | 12:02:18 | 16:42:44 | 9h 20m 51s |
| 2025-Dec-28, Sunday | 07:22:09 | 12:02:48 | 16:43:26 | 9h 21m 17s |
| 2025-Dec-29, Monday | 07:22:23 | 12:03:17 | 16:44:11 | 9h 21m 48s |
| 2025-Dec-30, Tuesday | 07:22:35 | 12:03:46 | 16:44:56 | 9h 22m 21s |
| 2025-Dec-31, Wednesday | 07:22:44 | 12:04:14 | 16:45:44 | 9h 23m 0s |
Day length in Boulder during the year on the chart:
Boulder on United States map:
Locations in the same time zone America/Denver
Denver (Colorado), Salt Lake City (Utah), El Paso (Texas), Albuquerque (New Mexico), Colorado Springs (Colorado), Ogden (Utah), Provo (Utah), Aurora (Colorado), Fort Collins (Colorado), Lakewood (Colorado), Pueblo (Colorado), Thornton (Colorado), Grand Junction (Colorado), West Valley City (Utah), Las Cruces (New Mexico), Greeley (Colorado), Billings (Montana), Arvada (Colorado), St. George (Utah), West Jordan (Utah), Westminster (Colorado), Centennial (Colorado), Santa Fe (New Mexico), Highlands Ranch (Colorado), Logan (Utah), Longmont (Colorado), Orem (Utah), Rio Rancho (New Mexico), Sandy (Utah), Lafayette (Colorado)
Largest populated areas in United States
New York (New York), Los Angeles (California), Chicago (Illinois), Miami (Florida), Dallas (Texas), Philadelphia (Pennsylvania), Houston (Texas), Washington (District of Columbia), Atlanta (Georgia), Boston (Massachusetts), Phoenix (Arizona), Seattle (Washington), San Francisco (California), Detroit (Michigan), San Diego (California), Minneapolis (Minnesota), Tampa (Florida), Denver (Colorado), Brooklyn (New York), Queens (New York), Baltimore (Maryland), Riverside (California), St. Louis (Missouri), Las Vegas (Nevada), Portland (Oregon), San Antonio (Texas), Sacramento (California), San Jose (California), Orlando (Florida), Cleveland (Ohio)
Countries closest to United States
*Calculation of distances from capital to capital
Daylight Hours FAQ: 10 Most Googled Questions Answered
Daylight hours refer to the period between sunrise and sunset. This duration changes throughout the year based on season and geographic location.
Earth's 23.5° axial tilt causes uneven sunlight distribution. Your hemisphere receives less direct sunlight in winter (shorter days) and more in summer (longer days).
Northern Hemisphere: June 20-22 (summer solstice).
Southern Hemisphere: December 21-23.
Near polar circles, the sun doesn't set for 24 hours.
Northern Hemisphere: December 21-22 (winter solstice).
Southern Hemisphere: June 20-21.
The closer to poles, the more extreme variations:
- Equator: ~12-hour days year-round
- Polar regions: Midnight sun/polar nights occur
Miami's lower latitude means:
- Winter days are longer than NY's
- Summer days are slightly shorter
During equinoxes:
- Spring: March 20-21
- Fall: September 22-23
Most rapid change near equinoxes: 2-4 minutes daily.
Slowest change near solstices: <1 minute daily.
Reliable tools:
- Timeanddate.com
- SunCalc.org
- Photographer's Ephemeris app
Yes. Reduced winter sunlight may cause:
- Seasonal Affective Disorder (SAD)
- Vitamin D deficiency
Solution: Light therapy lamps & midday walks