Daylight hours in Oulu
Oulu gets 21h 54m of daylight on its longest day in June, and 3h 41m on its shortest in December — a difference of 18h 12m across the year.
How fast the days change
Around 11 May, Oulu gains or loses about 7.1 minutes of daylight every day.
That is quick enough to notice week to week, which is why spring seems to arrive all at once this far from the equator.
Sunrise and sunset by month
On the 15th of each month, in Europe/Helsinki local time, daylight saving included.
| Month | Sunrise | Sunset | Daylight | Solar noon |
|---|---|---|---|---|
| January | 09:56 | 14:58 | 5h 02m | 12:27 |
| February | 08:17 | 16:46 | 8h 29m | 12:32 |
| March | 06:36 | 18:17 | 11h 41m | 12:27 |
| April | 05:42 | 20:54 | 15h 12m | 13:18 |
| May | 03:52 | 22:36 | 18h 44m | 13:14 |
| June | 02:21 | 00:15 | 21h 54m | 13:18 |
| July | 03:16 | 23:31 | 20h 15m | 13:24 |
| August | 05:03 | 21:41 | 16h 38m | 13:22 |
| September | 06:39 | 19:46 | 13h 07m | 13:13 |
| October | 08:11 | 17:56 | 9h 46m | 13:03 |
| November | 08:55 | 15:10 | 6h 15m | 12:02 |
| December | 10:22 | 14:03 | 3h 41m | 12:13 |
Solstices and equinoxes
| Date | Sunrise | Sunset | Daylight | |
|---|---|---|---|---|
| March equinox | 20 Mar | 06:18 | 18:32 | 12h 14m |
| June solstice | 21 Jun | 02:18 | 00:21 | 22h 03m |
| September equinox | 22 Sep | 07:00 | 19:20 | 12h 20m |
| December solstice | 21 Dec | 10:29 | 14:03 | 3h 34m |
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 Finland
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.