Daylight hours in Porto
Porto gets 15h 07m of daylight on its longest day in June, and 9h 14m on its shortest in December — a difference of 5h 54m across the year.
How fast the days change
Around 17 March, Porto gains or loses about 2.8 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/Lisbon local time, daylight saving included.
| Month | Sunrise | Sunset | Daylight | Solar noon |
|---|---|---|---|---|
| January | 07:57 | 17:30 | 9h 33m | 12:43 |
| February | 07:28 | 18:08 | 10h 39m | 12:48 |
| March | 06:45 | 18:40 | 11h 55m | 12:43 |
| April | 06:55 | 20:13 | 13h 19m | 13:34 |
| May | 06:16 | 20:45 | 14h 29m | 13:30 |
| June | 06:01 | 21:08 | 15h 07m | 13:34 |
| July | 06:14 | 21:05 | 14h 51m | 13:40 |
| August | 06:44 | 20:33 | 13h 50m | 13:38 |
| September | 07:15 | 19:44 | 12h 29m | 13:29 |
| October | 07:46 | 18:54 | 11h 08m | 13:20 |
| November | 07:22 | 17:15 | 9h 53m | 12:19 |
| December | 07:52 | 17:06 | 9h 14m | 12:29 |
Solstices and equinoxes
| Date | Sunrise | Sunset | Daylight | |
|---|---|---|---|---|
| March equinox | 20 Mar | 06:37 | 18:46 | 12h 09m |
| June solstice | 21 Jun | 06:01 | 21:10 | 15h 09m |
| September equinox | 22 Sep | 07:22 | 19:32 | 12h 10m |
| December solstice | 21 Dec | 07:56 | 17:08 | 9h 12m |
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 Portugal
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.