Is Dublin or Belfast better for the northern lights?

Belfast sits closer to the oval, at 57.3 degrees geomagnetic against 56.1. 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, Dublin or Belfast?

Belfast, with 15.1 hours of civil night on December 15 against 14.9 in Dublin.

What Kp do Dublin and Belfast need?

By SWPC's rule of 66 degrees at Kp 0 and 2 degrees per step, Dublin needs about Kp 5 and Belfast Kp 5 for the average oval edge to sit overhead.

When is it too light for aurora in Dublin and Belfast?

Dublin: never, every night has civil darkness. Belfast: never, every night has civil darkness.

Which is clearer, Dublin or Belfast?

Dublin, with 75% mean cloud in the months with 4 hours or more of civil night against 77% in Belfast (NASA POWER, 2001 to 2020).

Comparison

Dublin vs Belfast for the northern lights

Answer

Belfast sits 1.2 degrees higher on the IGRF-14 dipole, 57.3 against 56.1. By SWPC's oval-edge rule Belfast needs about Kp 5 for the average edge to sit overhead and Dublin Kp 5. On the map Belfast is also closer to the pole, by 1.3 degrees.

56.1° / 57.3°

dipole latitude

Side by side

Computed figures for both towns
Figure	Dublin	Belfast
Dipole latitude	56.1°	57.3°
Kp for the oval edge overhead	Kp 5	Kp 5
Civil night, December 15	14.9 h	15.1 h
Dark-season days	365	365
Nights with no civil darkness	0	0
Dark-month cloud, NASA POWER	75%	77%
Solar midnight, December 15	00:20	00:19

Dublin sits at 56.1 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. Belfast 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.

Civil night month by month

On December 15 Dublin has 14.9 hours of civil night and Belfast 15.1. Across the 15th of each month, Dublin is darker in 6 months and Belfast in 4. The widest gap comes in June, when Dublin has 0.4 more hours.

Hours of civil night on the 15th of each month, 2026
Month	Dublin	Belfast	Difference
January	14.4 h	14.6 h	-0.2 h
February	12.8 h	12.8 h	+0.0 h
March	10.9 h	10.9 h	+0.0 h
April	8.6 h	8.5 h	+0.1 h
May	6.5 h	6.2 h	+0.3 h
June	5.1 h	4.7 h	+0.4 h
July	5.8 h	5.4 h	+0.4 h
August	7.8 h	7.6 h	+0.2 h
September	10.1 h	10.0 h	+0.1 h
October	12.1 h	12.2 h	-0.1 h
November	14.0 h	14.1 h	-0.1 h
December	14.9 h	15.1 h	-0.2 h

Difference: Dublin minus Belfast. Each figure links to that town's month page.

Season and midnight sun

Dublin has some civil darkness every night of 2026, and clears Glow's 4-hour dark-season bar every evening. Belfast 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 142 km apart by great circle. In the dark months both average about 76% cloud in NASA POWER's 2001 to 2020 record. Dublin's best month by civil night times clear sky is November. Belfast's best month by civil night times clear sky is December. Time zones: Europe/Dublin and Europe/London.

For tonight, open the live pages for Dublin and Belfast, which carry the live OVATION cell.

Questions

Is Dublin or Belfast better for the northern lights?: Belfast sits closer to the oval, at 57.3 degrees geomagnetic against 56.1. 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, Dublin or Belfast?: Belfast, with 15.1 hours of civil night on December 15 against 14.9 in Dublin.
What Kp do Dublin and Belfast need?: By SWPC's rule of 66 degrees at Kp 0 and 2 degrees per step, Dublin needs about Kp 5 and Belfast Kp 5 for the average oval edge to sit overhead.
When is it too light for aurora in Dublin and Belfast?: Dublin: never, every night has civil darkness. Belfast: never, every night has civil darkness.
Which is clearer, Dublin or Belfast?: Dublin, with 75% mean cloud in the months with 4 hours or more of civil night against 77% in Belfast (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.