Daylight hours in Portsmouth
Portsmouth gets 16h 29m of daylight on its longest day in June, and 7h 59m on its shortest in December — a difference of 8h 30m across the year.
How fast the days change
Around 17 March, Portsmouth gains or loses about 3.9 minutes of daylight every day.
Enough to notice over a fortnight, though the seasons arrive more gently here than further from the equator.
Sunrise and sunset by month
On the 15th of each month, in Europe/London local time, daylight saving included.
| Month | Sunrise | Sunset | Daylight | Solar noon |
|---|---|---|---|---|
| January | 08:00 | 16:27 | 8h 27m | 12:13 |
| February | 07:16 | 17:20 | 10h 04m | 12:18 |
| March | 06:17 | 18:08 | 11h 51m | 12:13 |
| April | 06:09 | 19:59 | 13h 49m | 13:04 |
| May | 05:15 | 20:46 | 15h 31m | 13:00 |
| June | 04:50 | 21:19 | 16h 29m | 13:04 |
| July | 05:08 | 21:12 | 16h 04m | 13:10 |
| August | 05:52 | 20:25 | 14h 33m | 13:08 |
| September | 06:39 | 19:19 | 12h 39m | 12:59 |
| October | 07:27 | 18:12 | 10h 45m | 12:50 |
| November | 07:20 | 16:17 | 8h 58m | 11:48 |
| December | 08:00 | 15:58 | 7h 59m | 11:59 |
Solstices and equinoxes
| Date | Sunrise | Sunset | Daylight | |
|---|---|---|---|---|
| March equinox | 20 Mar | 06:06 | 18:16 | 12h 10m |
| June solstice | 21 Jun | 04:50 | 21:21 | 16h 31m |
| September equinox | 22 Sep | 06:50 | 19:03 | 12h 13m |
| December solstice | 21 Dec | 08:04 | 16:00 | 7h 57m |
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 Kingdom
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.