Connacht, Ireland
Northern lights in Sligo
Answer
Tonight
Waiting on darkness
It is not civil-dark yet. The next dusk is listed below.
Observed 11:49 UTC, forecast 13:20 UTC, 91 min lead
Clock times in Europe/Dublin
Storm level needed
Sligo sits at 54.27N 8.47W in Connacht, Ireland. The IGRF-14 centered dipole puts Sligo at 57.3 degrees geomagnetic latitude, 3.1 degrees closer to the magnetic pole than its map latitude suggests. Sligo sits at 57.3 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.
"aurora is commonly visible at high latitudes (northern Michigan and Maine)"
The nearest other Glow towns are Omagh (84 km), Letterkenny (89 km), Athlone (100 km). Omagh sits 0.1 degrees higher on the dipole and needs the same Kp.
Approximate: SWPC calls its Kp to latitude rule an average, and a centered dipole can differ by a degree from fuller field models. How the storm level is matched
The year in darkness
Every night of 2026 at Sligo has some civil darkness; the shortest month sample still has 4.8 hours. Every evening of the year at Sligo clears Glow's dark-season bar of 4 hours of civil night between 18:00 and 06:00. Sligo's longest night of the year, Dec 18, has 15 h 5 min of civil night.
Solar midnight at Sligo, when the sun is lowest, falls at 00:29 on local clocks on December 15 and 01:34 on June 15. That is 29 min after midnight in December and 1 h 34 min after midnight in June, the gap set by daylight saving and the equation of time. So at Sligo the darkest hour sits near the middle of SWPC's 10 PM to 2 AM window in winter.
Month by month
| Month | Night | Civil | Cloud | Clear dark | |
|---|---|---|---|---|---|
| Jan | 14.5 h | 11.6 h | 84% | 2.3 h | |
| Feb | 12.8 h | 10.1 h | 82% | 2.3 h | |
| Mar | 10.8 h | 8.0 h | 81% | 2.1 h | |
| Apr | 8.5 h | 4.9 h | 77% | 2.0 h | |
| May | 6.2 h | 0.0 h | 76% | 1.5 h | |
| Jun | 4.8 h | 0.0 h | 81% | 0.9 h | |
| Jul | 5.5 h | 0.0 h | 85% | 0.8 h | |
| Aug | 7.6 h | 3.5 h | 83% | 1.3 h | |
| Sep | 10.0 h | 7.0 h | 80% | 2.0 h | |
| Oct | 12.2 h | 9.4 h | 79% | 2.6 h | |
| Nov | 14.1 h | 11.2 h | 82% | 2.5 h | |
| Dec | 15.1 h | 12.1 h | 83% | 2.6 hbest |
By the 15th-of-the-month sample, December is the darkest month at Sligo with 15.1 hours of civil night and June the lightest at 4.8. Across the year Sligo gets 3,712 hours of civil night. Astronomical night at Sligo, the sun 18 degrees or more below the horizon, lasts 12.1 hours on December 15.
NASA POWER's 2001 to 2020 all-hours climatology puts mean cloud amount for the 1 degree cell around Sligo at 81% across the year, from 76% in May to 85% in July. In the months with at least 4 hours of civil night Sligo averages 81%, against a median of 75% for Glow towns in Ireland.
Multiplying civil night by the clear share of the sky gives December the best score, 2.6 hours, ahead of October at 2.6. Sligo's equinox months score 2.1 in March and 2.0 in September, the weeks SWPC links with larger storms.
Kp history
From 1996 to 2025, the GFZ Potsdam record shows a 3-hour Kp of 5 or more, the level that puts the average oval edge over Sligo, on 10% of days. At Sligo's level the share runs from 5% in December to 14% in September, while storm days with Kp 5 or more made up 10%.
Share of UTC days in each calendar month whose highest 3-hour Kp reached Kp 5. Kp history by year
Moon, next 30 nights
Over the 30 nights from Oct 2, the new moon falls on Oct 10 and the full moon on Oct 26, in Europe/Dublin dates. 15 of the 30 nights at Sligo have at least 2 moon-free dark hours inside 10 PM to 2 AM, and Oct 5 has the most at 4 h. Tonight Sligo has 11 h 14 min of civil night, 2 h of it with the moon down.
- 2
57% lit
2.0 h
- 3
46% lit
3.4 h
- 4
34% lit
4.9 h
- 5
24% lit
6.5 h
- 6
15% lit
8.0 h
- 7
8% lit
9.5 h
- 8
3% lit
10.9 h
- 9
1% lit
11.7 h
- 10
0% lit
11.8 h
- 11
2% lit
11.9 h
- 12
6% lit
11.9 h
- 13
11% lit
12.0 h
- 14
18% lit
12.0 h
- 15
26% lit
11.4 h
- 16
34% lit
10.5 h
- 17
43% lit
9.4 h
- 18
53% lit
8.2 h
- 19
62% lit
6.9 h
- 20
72% lit
5.6 h
- 21
80% lit
4.3 h
- 22
88% lit
3.0 h
- 23
94% lit
1.6 h
- 24
98% lit
0.2 h
- 25
100% lit
0.0 h
- 26
99% lit
0.0 h
- 27
95% lit
0.0 h
- 28
89% lit
0.0 h
- 29
81% lit
0.9 h
- 30
71% lit
2.2 h
- 31
60% lit
3.7 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.
Within Ireland
Among the 2 Glow towns in Connacht, Sligo ranks 1st by dipole latitude against a regional median of 56.9 degrees, the highest of them. Among the 24 Glow towns in Ireland, Sligo ranks 2nd by dipole latitude against a national median of 56.1 degrees; Letterkenny sits highest at 57.9. On December 15 Sligo gets 15.1 hours of civil night, 2nd longest of 24 in Ireland, where the median is 14.9.
Questions
- Can you see the northern lights in Sligo?
- Sligo sits at 57.3 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. Clear, dark sky over Sligo still decides it.
- When is it dark enough in Sligo?
- Every night at Sligo has civil darkness. Tonight has 11 h 14 min, and December 15 has 15.1 hours.
- What is the best month for aurora in Sligo?
- December, by civil night at Sligo times the clear share of the sky from NASA POWER's 2001 to 2020 average.
- How cloudy is Sligo in the dark months?
- About 81% mean cloud amount over Sligo in the months with at least 4 hours of civil night, from NASA POWER's 2001 to 2020 all-hours climatology.
- How often is activity high enough for Sligo?
- A 3-hour Kp of 5 or more, the level that puts the average oval edge overhead, occurred on 10% of days from 1996 to 2025 in the GFZ Potsdam record.
Nearby and related
Nearest Glow towns
Sligo by month
Region and comparisons