Daylight hours in Roseau
Roseau gets 13h 02m of daylight on its longest day in June, and 11h 13m on its shortest in December — a difference of 1h 48m across the year.
How fast the days change
Around 17 March, Roseau gains or loses about 0.9 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/Dominica local time, daylight saving included.
| Month | Sunrise | Sunset | Daylight | Solar noon |
|---|---|---|---|---|
| January | 06:35 | 17:54 | 11h 19m | 12:15 |
| February | 06:30 | 18:09 | 11h 39m | 12:19 |
| March | 06:13 | 18:15 | 12h 03m | 12:14 |
| April | 05:51 | 18:20 | 12h 29m | 12:05 |
| May | 05:36 | 18:27 | 12h 51m | 12:01 |
| June | 05:35 | 18:37 | 13h 02m | 12:06 |
| July | 05:43 | 18:40 | 12h 57m | 12:11 |
| August | 05:50 | 18:29 | 12h 38m | 12:10 |
| September | 05:54 | 18:07 | 12h 13m | 12:00 |
| October | 05:57 | 17:45 | 11h 48m | 11:51 |
| November | 06:07 | 17:32 | 11h 25m | 11:50 |
| December | 06:24 | 17:37 | 11h 13m | 12:00 |
Solstices and equinoxes
| Date | Sunrise | Sunset | Daylight | |
|---|---|---|---|---|
| March equinox | 20 Mar | 06:09 | 18:16 | 12h 07m |
| June solstice | 21 Jun | 05:36 | 18:38 | 13h 02m |
| September equinox | 22 Sep | 05:54 | 18:01 | 12h 07m |
| December solstice | 21 Dec | 06:27 | 17:40 | 11h 13m |
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.
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.