Daylight hours in San Antonio
San Antonio gets 14h 01m of daylight on its longest day in June, and 10h 16m on its shortest in December — a difference of 3h 45m across the year.
How fast the days change
Around 17 March, San Antonio gains or loses about 1.8 minutes of daylight every day.
Barely perceptible — near the equator the length of the day hardly changes at all, and the seasons announce themselves through rain and heat instead.
Sunrise and sunset by month
On the 15th of each month, in America/Chicago local time, daylight saving included.
| Month | Sunrise | Sunset | Daylight | Solar noon |
|---|---|---|---|---|
| January | 07:29 | 17:57 | 10h 28m | 12:43 |
| February | 07:12 | 18:23 | 11h 10m | 12:48 |
| March | 07:43 | 19:42 | 11h 59m | 13:42 |
| April | 07:07 | 20:00 | 12h 53m | 13:33 |
| May | 06:41 | 20:19 | 13h 38m | 13:30 |
| June | 06:33 | 20:35 | 14h 01m | 13:34 |
| July | 06:44 | 20:35 | 13h 51m | 13:40 |
| August | 07:02 | 20:14 | 13h 12m | 13:38 |
| September | 07:18 | 19:39 | 12h 20m | 13:29 |
| October | 07:35 | 19:03 | 11h 28m | 13:19 |
| November | 06:58 | 17:38 | 10h 41m | 12:18 |
| December | 07:21 | 17:37 | 10h 16m | 12:29 |
Solstices and equinoxes
| Date | Sunrise | Sunset | Daylight | |
|---|---|---|---|---|
| March equinox | 20 Mar | 07:37 | 19:45 | 12h 08m |
| June solstice | 21 Jun | 06:34 | 20:36 | 14h 02m |
| September equinox | 22 Sep | 07:22 | 19:30 | 12h 08m |
| December solstice | 21 Dec | 07:24 | 17:39 | 10h 15m |
The equinoxes give almost exactly twelve hours of daylight everywhere on earth — "almost" because sunrise is defined by the sun's upper edge rather than its centre, and the atmosphere bends its light over the horizon before it has really arrived. Both lengthen the day by a few minutes.
Other cities in United States
Assumptions
- Sea-level horizon. Hills, mountains and buildings all delay sunrise and bring sunset forward, sometimes by a lot in a valley.
- Standard refraction. Sunrise is taken at −0.833°, allowing for the sun's disc and average atmospheric bending. Unusual air conditions shift it by a minute or two.
- Local clock time, with daylight saving applied from the IANA timezone database.