Is Reykjavík or Hafnarfjörður better for the northern lights?

Reykjavík sits closer to the oval, at 68.8 degrees geomagnetic against 68.7. 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, Reykjavík or Hafnarfjörður?

Reykjavík, with 17.0 hours of civil night on December 15 against 17.0 in Hafnarfjörður.

What Kp do Reykjavík and Hafnarfjörður need?

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

When is it too light for aurora in Reykjavík and Hafnarfjörður?

Reykjavík: May 17 to July 25. Hafnarfjörður: May 17 to July 25.

Which is clearer, Reykjavík or Hafnarfjörður?

Reykjavík, with 79% mean cloud in the months with 4 hours or more of civil night against 79% in Hafnarfjörður (NASA POWER, 2001 to 2020).

Comparison

Reykjavík vs Hafnarfjörður for the northern lights

Answer

Reykjavík sits 0.1 degrees higher on the IGRF-14 dipole, 68.8 against 68.7. By SWPC's oval-edge rule Reykjavík needs about Kp 0 for the average edge to sit overhead and Hafnarfjörður Kp 0. On the map Reykjavík is also closer to the pole, by 0.1 degrees.

68.8° / 68.7°

dipole latitude

Side by side

Computed figures for both towns
Figure	Reykjavík	Hafnarfjörður
Dipole latitude	68.8°	68.7°
Kp for the oval edge overhead	Kp 0	Kp 0
Civil night, December 15	17.0 h	17.0 h
Dark-season days	269	270
Nights with no civil darkness	70	70
Dark-month cloud, NASA POWER	79%	79%
Solar midnight, December 15	01:23	01:23

Reykjavík sits at 68.8 degrees geomagnetic, inside SWPC's 60 to 75 degree band, where aurora can be seen on more than half of all nights. No storm is needed: by SWPC's rule the average oval edge is overhead at Kp 0. Hafnarfjörður sits at 68.7 degrees geomagnetic, inside SWPC's 60 to 75 degree band, where aurora can be seen on more than half of all nights. No storm is needed: by SWPC's rule the average oval edge is overhead at Kp 0.

Civil night month by month

On December 15 Reykjavík has 17.0 hours of civil night and Hafnarfjörður 17.0. Across the 15th of each month, Reykjavík is darker in 2 months and Hafnarfjörður in 1. The widest gap comes in May, when Hafnarfjörður has 0.2 more hours.

Hours of civil night on the 15th of each month, 2026
Month	Reykjavík	Hafnarfjörður	Difference
January	16.1 h	16.1 h	+0.0 h
February	13.5 h	13.4 h	+0.1 h
March	10.5 h	10.5 h	+0.0 h
April	6.8 h	6.8 h	+0.0 h
May	1.2 h	1.4 h	-0.2 h
June	0.0 h	0.0 h	+0.0 h
July	0.0 h	0.0 h	+0.0 h
August	5.3 h	5.3 h	+0.0 h
September	9.2 h	9.2 h	+0.0 h
October	12.5 h	12.5 h	+0.0 h
November	15.4 h	15.3 h	+0.1 h
December	17.0 h	17.0 h	+0.0 h

Difference: Reykjavík minus Hafnarfjörður. Each figure links to that town's month page.

Season and midnight sun

Reykjavík has no civil darkness from May 17 to July 25, 70 nights in 2026, and its dark season, 4 or more evening hours of civil night, lasts 269 days. Hafnarfjörður has no civil darkness from May 17 to July 25, 70 nights in 2026, and its dark season, 4 or more evening hours of civil night, lasts 270 days.

Distance, cloud and time zones

The two towns are 8 km apart by great circle. In the dark months both average about 79% cloud in NASA POWER's 2001 to 2020 record. Reykjavík's best month by civil night times clear sky is December. Hafnarfjörður's best month by civil night times clear sky is December. Time zones: Atlantic/Reykjavik and Atlantic/Reykjavik.

For tonight, open the live pages for Reykjavík and Hafnarfjörður, which carry the live OVATION cell.

Questions

Is Reykjavík or Hafnarfjörður better for the northern lights?: Reykjavík sits closer to the oval, at 68.8 degrees geomagnetic against 68.7. 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, Reykjavík or Hafnarfjörður?: Reykjavík, with 17.0 hours of civil night on December 15 against 17.0 in Hafnarfjörður.
What Kp do Reykjavík and Hafnarfjörður need?: By SWPC's rule of 66 degrees at Kp 0 and 2 degrees per step, Reykjavík needs about Kp 0 and Hafnarfjörður Kp 0 for the average oval edge to sit overhead.
When is it too light for aurora in Reykjavík and Hafnarfjörður?: Reykjavík: May 17 to July 25. Hafnarfjörður: May 17 to July 25.
Which is clearer, Reykjavík or Hafnarfjörður?: Reykjavík, with 79% mean cloud in the months with 4 hours or more of civil night against 79% in Hafnarfjörður (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.