Is Cork or Limerick better for the northern lights?

Limerick sits closer to the oval, at 55.8 degrees geomagnetic against 55.0. Darkness, cloud and your dates decide the rest; the tables on this page show both towns month by month.

Which has longer nights in December, Cork or Limerick?

Limerick, with 14.8 hours of civil night on December 15 against 14.7 in Cork.

What Kp do Cork and Limerick need?

By SWPC's rule of 66 degrees at Kp 0 and 2 degrees per step, Cork needs about Kp 6 and Limerick Kp 6 for the average oval edge to sit overhead.

When is it too light for aurora in Cork and Limerick?

Cork: never, every night has civil darkness. Limerick: never, every night has civil darkness.

Which is clearer, Cork or Limerick?

Cork, with 70% mean cloud in the months with 4 hours or more of civil night against 76% in Limerick (NASA POWER, 2001 to 2020).

Comparison

Cork vs Limerick for the northern lights

Answer

Limerick sits 0.8 degrees higher on the IGRF-14 dipole, 55.8 against 55.0. By SWPC's oval-edge rule Limerick needs about Kp 6 for the average edge to sit overhead and Cork Kp 6. On the map Limerick is also closer to the pole, by 0.8 degrees.

55.0° / 55.8°

dipole latitude

Side by side

Computed figures for both towns
Figure	Cork	Limerick
Dipole latitude	55.0°	55.8°
Kp for the oval edge overhead	Kp 6	Kp 6
Civil night, December 15	14.7 h	14.8 h
Dark-season days	365	365
Nights with no civil darkness	0	0
Dark-month cloud, NASA POWER	70%	76%
Solar midnight, December 15	00:29	00:30

Cork sits at 55.0 degrees geomagnetic. By SWPC's rule the average oval edge is overhead at Kp 6, and aurora is usually visible on the northern horizon at G1 (Kp 5) or less. Limerick sits at 55.8 degrees geomagnetic. By SWPC's rule the average oval edge is overhead at Kp 6, and aurora is usually visible on the northern horizon at G1 (Kp 5) or less.

Civil night month by month

On December 15 Cork has 14.7 hours of civil night and Limerick 14.8. Across the 15th of each month, Cork is darker in 5 months and Limerick in 4. The widest gap comes in May, when Cork has 0.2 more hours.

Hours of civil night on the 15th of each month, 2026
Month	Cork	Limerick	Difference
January	14.3 h	14.4 h	-0.1 h
February	12.7 h	12.8 h	-0.1 h
March	10.9 h	10.9 h	+0.0 h
April	8.8 h	8.7 h	+0.1 h
May	6.8 h	6.6 h	+0.2 h
June	5.5 h	5.3 h	+0.2 h
July	6.1 h	5.9 h	+0.2 h
August	8.0 h	7.9 h	+0.1 h
September	10.1 h	10.1 h	+0.0 h
October	12.1 h	12.1 h	+0.0 h
November	13.8 h	13.9 h	-0.1 h
December	14.7 h	14.8 h	-0.1 h

Difference: Cork minus Limerick. Each figure links to that town's month page.

Season and midnight sun

Cork has some civil darkness every night of 2026, and clears Glow's 4-hour dark-season bar every evening. Limerick has some civil darkness every night of 2026, and clears Glow's 4-hour dark-season bar every evening.

Distance, cloud and time zones

The two towns are 86 km apart by great circle. In the dark months Cork averages 70% cloud and Limerick 76%, from NASA POWER's 2001 to 2020 record. Cork's best month by civil night times clear sky is November. Limerick's best month by civil night times clear sky is November. Time zones: Europe/Dublin and Europe/Dublin.

For tonight, open the live pages for Cork and Limerick, which carry the live OVATION cell.

Questions

Is Cork or Limerick better for the northern lights?: Limerick sits closer to the oval, at 55.8 degrees geomagnetic against 55.0. Darkness, cloud and your dates decide the rest; the tables on this page show both towns month by month.
Which has longer nights in December, Cork or Limerick?: Limerick, with 14.8 hours of civil night on December 15 against 14.7 in Cork.
What Kp do Cork and Limerick need?: By SWPC's rule of 66 degrees at Kp 0 and 2 degrees per step, Cork needs about Kp 6 and Limerick Kp 6 for the average oval edge to sit overhead.
When is it too light for aurora in Cork and Limerick?: Cork: never, every night has civil darkness. Limerick: never, every night has civil darkness.
Which is clearer, Cork or Limerick?: Cork, with 70% mean cloud in the months with 4 hours or more of civil night against 76% in Limerick (NASA POWER, 2001 to 2020).

Sources and verification

IGRF-14 coefficients, NOAA NCEIhttps://www.ngdc.noaa.gov/IAGA/vmod/coeffs/igrf14coeffs.txt
SunCalchttps://github.com/mourner/suncalc
GeoNameshttps://www.geonames.org/export/
NASA POWER climatologyhttps://power.larc.nasa.gov/docs/services/api/temporal/climatology/
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.