July 21, 2026 · Castlereagh, Northern Ireland
Castlereagh has 16h 28m of daylight today. Sunrise is at 05:16 and sunset is at 21:45. All times are calculated astronomically for Castlereagh's exact coordinates.
Castlereagh lies at 55°N. At this latitude, day length varies significantly through the year — from roughly 7–8 hours in midwinter to 16–17 hours at midsummer.
Day length changes fastest near the spring and autumn equinoxes and slowest near the longest day and shortest day of the year. See the year chart to visualise how daylight hours shift month by month for Castlereagh, or see daylight hours for every day of the year.
The longest day in Castlereagh is around 17h 16m (around June 21). The shortest is around 7h 15m (around December 21). Days are currently getting shorter — losing about 3 minutes per day.
| Month | Day length | Sunrise | Sunset |
|---|---|---|---|
| January | 7h 48m | 08:39 | 16:27 |
| February | 9h 40m | 07:49 | 17:29 |
| March | 11h 42m | 06:42 | 18:25 |
| April | 13h 59m | 06:25 | 20:24 |
| May | 15h 60m | 05:21 | 21:21 |
| June | 17h 13m | 04:48 | 22:01 |
| July | 16h 47m | 05:06 | 21:54 |
| August | 15h 2m | 05:58 | 21:00 |
| September | 12h 51m | 06:55 | 19:45 |
| October | 10h 40m | 07:50 | 18:30 |
| November | 8h 34m | 07:52 | 16:26 |
| December | 7h 19m | 08:39 | 15:59 |