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