Is Trondheim or Stjørdalshalsen better for the northern lights?

Trondheim sits closer to the oval, at 63.0 degrees geomagnetic against 63.0. 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, Trondheim or Stjørdalshalsen?

Trondheim, with 16.8 hours of civil night on December 15 against 16.8 in Stjørdalshalsen.

What Kp do Trondheim and Stjørdalshalsen need?

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

When is it too light for aurora in Trondheim and Stjørdalshalsen?

Trondheim: May 20 to July 22. Stjørdalshalsen: May 20 to July 22.

Which is clearer, Trondheim or Stjørdalshalsen?

Trondheim, with 80% mean cloud in the months with 4 hours or more of civil night against 80% in Stjørdalshalsen (NASA POWER, 2001 to 2020).

Comparison

Trondheim vs Stjørdalshalsen for the northern lights

Answer

Trondheim sits 0.0 degrees higher on the IGRF-14 dipole, 63.0 against 63.0. By SWPC's oval-edge rule Trondheim needs about Kp 2 for the average edge to sit overhead and Stjørdalshalsen Kp 2. That reverses the map, where Stjørdalshalsen is 0.0 degrees closer to the pole.

63.0° / 63.0°

dipole latitude

Side by side

Computed figures for both towns
Figure	Trondheim	Stjørdalshalsen
Dipole latitude	63.0°	63.0°
Kp for the oval edge overhead	Kp 2	Kp 2
Civil night, December 15	16.8 h	16.8 h
Dark-season days	275	273
Nights with no civil darkness	64	64
Dark-month cloud, NASA POWER	80%	80%
Solar midnight, December 15	00:14	00:11

Trondheim sits at 63.0 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 2. Stjørdalshalsen sits at 63.0 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 2.

Civil night month by month

On December 15 Trondheim has 16.8 hours of civil night and Stjørdalshalsen 16.8. Across the 15th of each month, Trondheim is darker in 0 months and Stjørdalshalsen in 0. The widest gap comes in January, when Trondheim has 0.0 more hours.

Hours of civil night on the 15th of each month, 2026
Month	Trondheim	Stjørdalshalsen	Difference
January	16.0 h	16.0 h	+0.0 h
February	13.4 h	13.4 h	+0.0 h
March	10.6 h	10.6 h	+0.0 h
April	7.0 h	7.0 h	+0.0 h
May	2.2 h	2.2 h	+0.0 h
June	0.0 h	0.0 h	+0.0 h
July	0.0 h	0.0 h	+0.0 h
August	5.5 h	5.5 h	+0.0 h
September	9.3 h	9.3 h	+0.0 h
October	12.4 h	12.4 h	+0.0 h
November	15.2 h	15.2 h	+0.0 h
December	16.8 h	16.8 h	+0.0 h

Difference: Trondheim minus Stjørdalshalsen. Each figure links to that town's month page.

Season and midnight sun

Trondheim has no civil darkness from May 20 to July 22, 64 nights in 2026, and its dark season, 4 or more evening hours of civil night, lasts 275 days. Stjørdalshalsen has no civil darkness from May 20 to July 22, 64 nights in 2026, and its dark season, 4 or more evening hours of civil night, lasts 273 days.

Distance, cloud and time zones

The two towns are 27 km apart by great circle. In the dark months both average about 80% cloud in NASA POWER's 2001 to 2020 record. Trondheim's best month by civil night times clear sky is December. Stjørdalshalsen's best month by civil night times clear sky is December. Time zones: Europe/Oslo and Europe/Oslo.

For tonight, open the live pages for Trondheim and Stjørdalshalsen, which carry the live OVATION cell.

Questions

Is Trondheim or Stjørdalshalsen better for the northern lights?: Trondheim sits closer to the oval, at 63.0 degrees geomagnetic against 63.0. 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, Trondheim or Stjørdalshalsen?: Trondheim, with 16.8 hours of civil night on December 15 against 16.8 in Stjørdalshalsen.
What Kp do Trondheim and Stjørdalshalsen need?: By SWPC's rule of 66 degrees at Kp 0 and 2 degrees per step, Trondheim needs about Kp 2 and Stjørdalshalsen Kp 2 for the average oval edge to sit overhead.
When is it too light for aurora in Trondheim and Stjørdalshalsen?: Trondheim: May 20 to July 22. Stjørdalshalsen: May 20 to July 22.
Which is clearer, Trondheim or Stjørdalshalsen?: Trondheim, with 80% mean cloud in the months with 4 hours or more of civil night against 80% in Stjørdalshalsen (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.