Thornton, CO · 2026
Sunrise and sunset in Thornton, Colorado
Short answer
- Longest day
- 15 h 00 min
- Shortest day
- 9 h 20 min
Thornton daylight through 2026
Daylight in Thornton runs from 9 h 20 min on December 21 to 15 h 00 min on June 21, a seasonal swing of 5 h 40 min between June 21 and December 21. That swing ranks 93rd of 342 US cities of 100,000+, where 1st is the largest. Around the March equinox the city gets 12 h 09 min, and around the September equinox 12 h 09 min.
Thornton daylight by month
| Month | Average | Sunrise | Sunset |
|---|---|---|---|
| January | 9 h 43 min | 7:08 AM to 7:21 AM | 4:45 PM to 5:18 PM |
| February | 10 h 43 min | 6:34 AM to 7:07 AM | 5:19 PM to 5:50 PM |
| March | 11 h 58 min | 6:23 AM to 7:22 AM | 5:51 PM to 7:23 PM |
| April | 13 h 17 min | 6:01 AM to 6:43 AM | 7:24 PM to 7:53 PM |
| May | 14 h 24 min | 5:33 AM to 5:59 AM | 7:54 PM to 8:21 PM |
| June | 14 h 58 min | 5:30 AM to 5:34 AM | 8:22 PM to 8:32 PM |
| July | 14 h 40 min | 5:35 AM to 5:57 AM | 8:14 PM to 8:32 PM |
| August | 13 h 41 min | 5:58 AM to 6:26 AM | 7:32 PM to 8:13 PM |
| September | 12 h 26 min | 6:27 AM to 6:55 AM | 6:43 PM to 7:30 PM |
| October | 11 h 08 min | 6:56 AM to 7:27 AM | 5:58 PM to 6:41 PM |
| November | 9 h 59 min | 6:28 AM to 7:01 AM | 4:35 PM to 4:57 PM |
| December | 9 h 24 min | 7:02 AM to 7:21 AM | 4:34 PM to 4:44 PM |
Earliest sunrise, latest sunset and the clock
The earliest sunrise comes on June 9 at 5:30 AM and the latest sunset on June 22 at 8:32 PM. The latest sunrise is 7:27 AM on October 31. Daylight saving time starts and ends on March 8 and November 1, which shifts every clock time by an hour.
On standard time the clocks run 7 hours behind UTC, the time of the 105° W meridian. Thornton sits at 104.94° W, almost on that meridian, so clock noon and solar noon agree closely in winter. Solar noon is at 12:09 PM on January 15 and 1:05 PM on July 15.
Compared with nearby cities
Denver, the state capital, gets 1 minutes less daylight than Thornton on June 21 and 1 minutes more on December 21. Day length depends on latitude, so the table lists the paired cities from north to south.
| City | Latitude | June 21 | December 21 |
|---|---|---|---|
| Fort Collins, CO | 40.55° N | 15 h 05 min | 9 h 16 min |
| Greeley, CO | 40.42° N | 15 h 04 min | 9 h 17 min |
| Boulder, CO | 40.02° N | 15 h 01 min | 9 h 20 min |
| Thornton, CO | 39.92° N | 15 h 00 min | 9 h 20 min |
| Westminster, CO | 39.88° N | 15 h 00 min | 9 h 20 min |
| Arvada, CO | 39.83° N | 15 h 00 min | 9 h 21 min |
| Denver, CO | 39.76° N | 14 h 59 min | 9 h 21 min |
| Aurora, CO | 39.71° N | 14 h 59 min | 9 h 21 min |
| Lakewood, CO | 39.70° N | 14 h 59 min | 9 h 22 min |
| Centennial, CO | 39.59° N | 14 h 58 min | 9 h 22 min |
| Colorado Springs, CO | 38.87° N | 14 h 54 min | 9 h 27 min |
| Pueblo, CO | 38.27° N | 14 h 50 min | 9 h 30 min |
Questions people ask
What is the longest day of the year in Thornton?
June 21, 2026, with 15 h 00 min of daylight: sunrise 5:31 AM, sunset 8:31 PM.
What is the shortest day in Thornton?
December 21, 2026, with 9 h 20 min: sunrise 7:17 AM, sunset 4:38 PM.
When is the latest sunset in Thornton?
8:32 PM on June 22, 2026. The earliest sunset is 4:34 PM on December 3.
What time zone is Thornton in?
America/Denver. Clocks change on March 8 (to MDT) and November 1 (to MST) in 2026.
Sources and data as of
Data as of: computed for 2026 at the Census internal point of Thornton, 39.920° N, 104.941° W; time zone from Open-Meteo.
- 01SunCalc library (Vladimir Agafonkin), algorithms after Jean Meeus
- 02IANA time zone database (clock times and daylight saving rules)
How every number is computed: methodology. Spotted a wrong figure? Report an error.