Is Fairbanks or Tromsø better for the northern lights?

Tromsø sits closer to the oval, at 67.5 degrees geomagnetic against 65.7. 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, Fairbanks or Tromsø?

Tromsø, with 19.2 hours of civil night on December 15 against 17.2 in Fairbanks.

What Kp do Fairbanks and Tromsø need?

By SWPC's rule of 66 degrees at Kp 0 and 2 degrees per step, Fairbanks needs about Kp 1 and Tromsø Kp 0 for the average oval edge to sit overhead.

When is it too light for aurora in Fairbanks and Tromsø?

Fairbanks: May 13 to July 28. Tromsø: April 27 to August 14.

Which is clearer, Fairbanks or Tromsø?

Fairbanks, with 64% mean cloud in the months with 4 hours or more of civil night against 83% in Tromsø (NASA POWER, 2001 to 2020).

Comparison

Fairbanks vs Tromsø for the northern lights

Answer

Tromsø sits 1.8 degrees higher on the IGRF-14 dipole, 67.5 against 65.7. By SWPC's oval-edge rule Tromsø needs about Kp 0 for the average edge to sit overhead and Fairbanks Kp 1. On the map Tromsø is also closer to the pole, by 4.8 degrees.

65.7° / 67.5°

dipole latitude

Side by side

Computed figures for both towns
Figure	Fairbanks	Tromsø
Dipole latitude	65.7°	67.5°
Kp for the oval edge overhead	Kp 1	Kp 0
Civil night, December 15	17.2 h	19.2 h
Dark-season days	266	239
Nights with no civil darkness	77	110
Dark-month cloud, NASA POWER	64%	83%
Solar midnight, December 15	00:46	23:39

Fairbanks sits at 65.7 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 1. Tromsø sits at 67.5 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 Fairbanks has 17.2 hours of civil night and Tromsø 19.2. Across the 15th of each month, Fairbanks is darker in 4 months and Tromsø in 5. The widest gap comes in August, when Fairbanks has 4.4 more hours.

Hours of civil night on the 15th of each month, 2026
Month	Fairbanks	Tromsø	Difference
January	16.3 h	17.8 h	-1.5 h
February	13.5 h	14.0 h	-0.5 h
March	10.4 h	10.2 h	+0.2 h
April	6.6 h	4.8 h	+1.8 h
May	0.0 h	0.0 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	5.0 h	0.6 h	+4.4 h
September	9.2 h	8.4 h	+0.8 h
October	12.5 h	12.7 h	-0.2 h
November	15.5 h	16.6 h	-1.1 h
December	17.2 h	19.2 h	-2.0 h

Difference: Fairbanks minus Tromsø. Each figure links to that town's month page.

Season and midnight sun

Fairbanks has no civil darkness from May 13 to July 28, 77 nights in 2026, and its dark season, 4 or more evening hours of civil night, lasts 266 days. Tromsø has no civil darkness from April 27 to August 14, 110 nights in 2026, and its dark season, 4 or more evening hours of civil night, lasts 239 days.

Distance, cloud and time zones

The two towns are 5,025 km apart by great circle. In the dark months Fairbanks averages 64% cloud and Tromsø 83%, from NASA POWER's 2001 to 2020 record. Fairbanks's best month by civil night times clear sky is January. Tromsø's best month by civil night times clear sky is January. Time zones: America/Anchorage and Europe/Oslo.

For tonight, open the live pages for Fairbanks and Tromsø, which carry the live OVATION cell.

Questions

Is Fairbanks or Tromsø better for the northern lights?: Tromsø sits closer to the oval, at 67.5 degrees geomagnetic against 65.7. 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, Fairbanks or Tromsø?: Tromsø, with 19.2 hours of civil night on December 15 against 17.2 in Fairbanks.
What Kp do Fairbanks and Tromsø need?: By SWPC's rule of 66 degrees at Kp 0 and 2 degrees per step, Fairbanks needs about Kp 1 and Tromsø Kp 0 for the average oval edge to sit overhead.
When is it too light for aurora in Fairbanks and Tromsø?: Fairbanks: May 13 to July 28. Tromsø: April 27 to August 14.
Which is clearer, Fairbanks or Tromsø?: Fairbanks, with 64% mean cloud in the months with 4 hours or more of civil night against 83% in Tromsø (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.