Sunrise and Sunset times in Boulder, United States 
Today:
 Sunrise: 07:55:44
|
 Sunset: 16:42:52
|
Day Length: 8h 47m 8s
Time zone: America/Denver, UTC -7 h.
Latitude: 46.2358, Longitude: -112.12
Boulder
Montana, United States 
1 248 people
| Date | Sunrise | Solar Noon | Sunset | Day length |
|---|---|---|---|---|
| 2025-Dec-01, Monday | 07:51:17 | 12:17:42 | 16:44:07 | 8h 52m 50s |
| 2025-Dec-02, Tuesday | 07:52:26 | 12:18:05 | 16:43:44 | 8h 51m 18s |
| 2025-Dec-03, Wednesday | 07:53:34 | 12:18:29 | 16:43:24 | 8h 49m 50s |
| 2025-Dec-04, Thursday | 07:54:40 | 12:18:53 | 16:43:07 | 8h 48m 27s |
| 2025-Dec-05, Friday | 07:55:44 | 12:19:18 | 16:42:52 | 8h 47m 8s |
| 2025-Dec-06, Saturday | 07:56:47 | 12:19:44 | 16:42:40 | 8h 45m 53s |
| 2025-Dec-07, Sunday | 07:57:48 | 12:20:10 | 16:42:31 | 8h 44m 43s |
| 2025-Dec-08, Monday | 07:58:48 | 12:20:36 | 16:42:24 | 8h 43m 36s |
| 2025-Dec-09, Tuesday | 07:59:45 | 12:21:03 | 16:42:20 | 8h 42m 35s |
| 2025-Dec-10, Wednesday | 08:00:41 | 12:21:30 | 16:42:19 | 8h 41m 38s |
| 2025-Dec-11, Thursday | 08:01:34 | 12:21:58 | 16:42:21 | 8h 40m 47s |
| 2025-Dec-12, Friday | 08:02:26 | 12:22:26 | 16:42:26 | 8h 40m 0s |
| 2025-Dec-13, Saturday | 08:03:15 | 12:22:54 | 16:42:33 | 8h 39m 18s |
| 2025-Dec-14, Sunday | 08:04:02 | 12:23:23 | 16:42:43 | 8h 38m 41s |
| 2025-Dec-15, Monday | 08:04:47 | 12:23:52 | 16:42:56 | 8h 38m 9s |
| 2025-Dec-16, Tuesday | 08:05:30 | 12:24:21 | 16:43:12 | 8h 37m 42s |
| 2025-Dec-17, Wednesday | 08:06:10 | 12:24:50 | 16:43:30 | 8h 37m 20s |
| 2025-Dec-18, Thursday | 08:06:48 | 12:25:20 | 16:43:51 | 8h 37m 3s |
| 2025-Dec-19, Friday | 08:07:24 | 12:25:49 | 16:44:15 | 8h 36m 51s |
| 2025-Dec-20, Saturday | 08:07:57 | 12:26:19 | 16:44:41 | 8h 36m 44s |
| 2025-Dec-21, Sunday | 08:08:27 | 12:26:49 | 16:45:10 | 8h 36m 43s |
| 2025-Dec-22, Monday | 08:08:55 | 12:27:19 | 16:45:42 | 8h 36m 47s |
| 2025-Dec-23, Tuesday | 08:09:21 | 12:27:49 | 16:46:16 | 8h 36m 55s |
| 2025-Dec-24, Wednesday | 08:09:44 | 12:28:18 | 16:46:53 | 8h 37m 9s |
| 2025-Dec-25, Thursday | 08:10:04 | 12:28:48 | 16:47:32 | 8h 37m 28s |
| 2025-Dec-26, Friday | 08:10:22 | 12:29:18 | 16:48:14 | 8h 37m 52s |
| 2025-Dec-27, Saturday | 08:10:37 | 12:29:47 | 16:48:58 | 8h 38m 21s |
| 2025-Dec-28, Sunday | 08:10:49 | 12:30:16 | 16:49:44 | 8h 38m 55s |
| 2025-Dec-29, Monday | 08:10:59 | 12:30:46 | 16:50:33 | 8h 39m 34s |
| 2025-Dec-30, Tuesday | 08:11:05 | 12:31:14 | 16:51:23 | 8h 40m 18s |
| 2025-Dec-31, Wednesday | 08:11:10 | 12:31:43 | 16:52:16 | 8h 41m 6s |
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