Dún Laoghaire · April 2027
Northern lights in Dún Laoghaire in April 2027
Answer
April against the rest of the year
April cloud at Dún Laoghaire averages 73% in NASA POWER's 2001 to 2020 record, 2 points clearer than its yearly mean. No month at Dún Laoghaire is clearer. By civil night times clear sky, April scores 2.3 hours at Dún Laoghaire, 8th of 12. Dublin, 9 km away, averages the same 73%.
Civil night at Dún Laoghaire starts April at 9 h 40 min and reaches 7 h 31 min by April 30, 2.1 hours shorter. SWPC's 10 PM to 2 AM window is fully dark on every night. True astronomical darkness, the sun 18 degrees down, lasts 5.2 hours on the 15th.
April night by night
April opens toward a new moon on Apr 7, with full moon on Apr 20, in Europe/Dublin dates. Dún Laoghaire gets 138 hours of civil night with the moon below the horizon across the month. The best of them for moon-free darkness inside 10 PM to 2 AM: Apr 1 (4 h), Apr 2 (4 h), Apr 3 (4 h).
- 1
24% lit
8.9 h
- 2
16% lit
9.1 h
- 3
10% lit
9.2 h
- 4
5% lit
9.4 h
- 5
1% lit
9.4 h
- 6
0% lit
9.3 h
- 7
1% lit
8.7 h
- 8
5% lit
7.2 h
- 9
11% lit
5.7 h
- 10
18% lit
4.3 h
- 11
28% lit
3.2 h
- 12
39% lit
2.3 h
- 13
50% lit
1.7 h
- 14
62% lit
1.3 h
- 15
72% lit
1.0 h
- 16
82% lit
0.8 h
- 17
90% lit
0.5 h
- 18
95% lit
0.3 h
- 19
99% lit
0.0 h
- 20
100% lit
0.0 h
- 21
99% lit
0.8 h
- 22
95% lit
2.1 h
- 23
90% lit
3.3 h
- 24
84% lit
4.3 h
- 25
76% lit
5.0 h
- 26
68% lit
5.5 h
- 27
58% lit
5.9 h
- 28
49% lit
6.1 h
- 29
40% lit
6.3 h
- 30
30% lit
6.5 h
Each cell is the night that starts on that date. Hours are civil-dark time with the moon below the horizon; the green rule scales with them. Green outline: new moon. Bone outline: full moon.
Activity in past Aprils
Dún Laoghaire needs Kp 5 for the average oval edge to sit overhead. 106 of the 900 April days from 1996 to 2025 (12%) reached it in the GFZ Potsdam record, 4th of 12 months; storm days with Kp 5 or more made up 12%. Dún Laoghaire sits at 56.0 degrees geomagnetic. By SWPC's rule the average oval edge is overhead at Kp 5, and aurora is usually visible on the northern horizon at G1 (Kp 5) or less.
April across Ireland
Dún Laoghaire ranks 3rd in Ireland for civil night on April 15, behind Cork at 8.8 hours. Coming from March (10.9 hours at Dún Laoghaire), April loses darkness, and May brings shorter nights (6.5 hours on the 15th).
| Town | Civil night | Cloud |
|---|---|---|
| Cork | 8.8 h | 66% |
| Limerick | 8.7 h | 72% |
| Dún Laoghaire | 8.6 h | 73% |
| Dublin | 8.6 h | 73% |
Darkness and moon, every night
| Night | Civil | Astronomical | Moon-free dark | Moon-free, 10 PM to 2 AM | Moon lit |
|---|---|---|---|---|---|
| Thu Apr 1 | 9 h 40 min | 6 h 39 min | 8 h 56 min | 4 h | 24% |
| Fri Apr 2 | 9 h 35 min | 6 h 34 min | 9 h 6 min | 4 h | 16% |
| Sat Apr 3 | 9 h 31 min | 6 h 28 min | 9 h 14 min | 4 h | 10% |
| Sun Apr 4 | 9 h 26 min | 6 h 22 min | 9 h 22 min | 4 h | 5% |
| Mon Apr 5 | 9 h 22 min | 6 h 16 min | 9 h 22 min | 4 h | 1% |
| Tue Apr 6 | 9 h 17 min | 6 h 10 min | 9 h 17 min | 4 h | 0% |
| Wed Apr 7 | 9 h 13 min | 6 h 4 min | 8 h 40 min | 4 h | 1% |
| Thu Apr 8 | 9 h 9 min | 5 h 58 min | 7 h 12 min | 3 h 11 min | 5% |
| Fri Apr 9 | 9 h 4 min | 5 h 52 min | 5 h 42 min | 1 h 45 min | 11% |
| Sat Apr 10 | 9 h | 5 h 46 min | 4 h 19 min | 24 min | 18% |
| Sun Apr 11 | 8 h 55 min | 5 h 40 min | 3 h 10 min | 0 min | 28% |
| Mon Apr 12 | 8 h 51 min | 5 h 33 min | 2 h 20 min | 0 min | 39% |
| Tue Apr 13 | 8 h 46 min | 5 h 27 min | 1 h 44 min | 0 min | 50% |
| Wed Apr 14 | 8 h 42 min | 5 h 21 min | 1 h 19 min | 0 min | 62% |
| Thu Apr 15 | 8 h 37 min | 5 h 14 min | 1 h | 0 min | 72% |
| Fri Apr 16 | 8 h 33 min | 5 h 7 min | 45 min | 0 min | 82% |
| Sat Apr 17 | 8 h 28 min | 5 h | 31 min | 0 min | 90% |
| Sun Apr 18 | 8 h 24 min | 4 h 54 min | 17 min | 0 min | 95% |
| Mon Apr 19 | 8 h 20 min | 4 h 47 min | 2 min | 0 min | 99% |
| Tue Apr 20 | 8 h 15 min | 4 h 39 min | 0 min | 0 min | 100% |
| Wed Apr 21 | 8 h 11 min | 4 h 32 min | 49 min | 6 min | 99% |
| Thu Apr 22 | 8 h 6 min | 4 h 25 min | 2 h 7 min | 1 h 27 min | 95% |
| Fri Apr 23 | 8 h 2 min | 4 h 17 min | 3 h 19 min | 2 h 40 min | 90% |
| Sat Apr 24 | 7 h 57 min | 4 h 9 min | 4 h 17 min | 3 h 41 min | 84% |
| Sun Apr 25 | 7 h 53 min | 4 h 2 min | 5 h 1 min | 4 h | 76% |
| Mon Apr 26 | 7 h 49 min | 3 h 54 min | 5 h 31 min | 4 h | 68% |
| Tue Apr 27 | 7 h 44 min | 3 h 45 min | 5 h 52 min | 4 h | 58% |
| Wed Apr 28 | 7 h 40 min | 3 h 37 min | 6 h 7 min | 4 h | 49% |
| Thu Apr 29 | 7 h 35 min | 3 h 28 min | 6 h 18 min | 4 h | 40% |
| Fri Apr 30 | 7 h 31 min | 3 h 19 min | 6 h 27 min | 4 h | 30% |
Questions
- Can you see the northern lights in Dún Laoghaire in April?
- On dark, clear nights with enough activity. 30 of 30 nights at Dún Laoghaire have civil darkness, and 12% of past April days reached Kp 5.
- How dark is Dún Laoghaire in April?
- Dún Laoghaire averages 8.6 hours of civil night a night in April 2027, from 9 h 40 min on the 1st to 7 h 31 min on the last night.
- How cloudy is Dún Laoghaire in April?
- NASA POWER's 2001 to 2020 climatology gives Dún Laoghaire's 1 degree cell 73% mean cloud in April, against 75% for the whole year. It is an all-hours average, not a forecast.
- What is the best night in April 2027 for aurora in Dún Laoghaire?
- By darkness and moon alone, Apr 1, with 4 h of moon-free darkness inside 10 PM to 2 AM at Dún Laoghaire. Activity on that date will only be known hours ahead.
- Is April or May better in Dún Laoghaire?
- By civil night times the clear share, April scores 2.3 hours at Dún Laoghaire and May 1.8. April comes out ahead.
Sources and verification
- SunCalchttps://github.com/mourner/suncalc
- NASA POWER climatologyhttps://power.larc.nasa.gov/docs/services/api/temporal/climatology/
- GFZ Potsdam Kp indexhttps://kp.gfz.de/en/data
- NOAA SWPC, Tips on viewing the aurorahttps://www.spaceweather.gov/content/tips-viewing-aurora
Quoted figures last checked against their sources on 2026-09-30; next review 2026-12-31. Computed figures come from SunCalc and the IGRF-14 dipole as described in the methodology. Every quote is listed in the sources ledger.