Is Petrozavodsk or Kostomuksha better for the northern lights?

Kostomuksha sits closer to the oval, at 61.1 degrees geomagnetic against 57.9. 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, Petrozavodsk or Kostomuksha?

Kostomuksha, with 17.1 hours of civil night on December 15 against 16.4 in Petrozavodsk.

What Kp do Petrozavodsk and Kostomuksha need?

By SWPC's rule of 66 degrees at Kp 0 and 2 degrees per step, Petrozavodsk needs about Kp 5 and Kostomuksha Kp 3 for the average oval edge to sit overhead.

When is it too light for aurora in Petrozavodsk and Kostomuksha?

Petrozavodsk: May 29 to July 12. Kostomuksha: May 15 to July 27.

Which is clearer, Petrozavodsk or Kostomuksha?

Petrozavodsk, with 78% mean cloud in the months with 4 hours or more of civil night against 78% in Kostomuksha (NASA POWER, 2001 to 2020).

Comparison

Petrozavodsk vs Kostomuksha for the northern lights

Answer

Kostomuksha sits 3.2 degrees higher on the IGRF-14 dipole, 61.1 against 57.9. By SWPC's oval-edge rule Kostomuksha needs about Kp 3 for the average edge to sit overhead and Petrozavodsk Kp 5. On the map Kostomuksha is also closer to the pole, by 2.8 degrees.

57.9° / 61.1°

dipole latitude

Side by side

Computed figures for both towns
Figure	Petrozavodsk	Kostomuksha
Dipole latitude	57.9°	61.1°
Kp for the oval edge overhead	Kp 5	Kp 3
Civil night, December 15	16.4 h	17.1 h
Dark-season days	285	267
Nights with no civil darkness	45	74
Dark-month cloud, NASA POWER	78%	78%
Solar midnight, December 15	00:38	00:53

Petrozavodsk sits at 57.9 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. Kostomuksha sits at 61.1 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 3.

Civil night month by month

On December 15 Petrozavodsk has 16.4 hours of civil night and Kostomuksha 17.1. Across the 15th of each month, Petrozavodsk is darker in 6 months and Kostomuksha in 5. The widest gap comes in May, when Petrozavodsk has 3.5 more hours.

Hours of civil night on the 15th of each month, 2026
Month	Petrozavodsk	Kostomuksha	Difference
January	15.7 h	16.2 h	-0.5 h
February	13.3 h	13.5 h	-0.2 h
March	10.6 h	10.5 h	+0.1 h
April	7.4 h	6.7 h	+0.7 h
May	3.5 h	0.0 h	+3.5 h
June	0.0 h	0.0 h	+0.0 h
July	1.2 h	0.0 h	+1.2 h
August	6.0 h	5.1 h	+0.9 h
September	9.4 h	9.2 h	+0.2 h
October	12.4 h	12.5 h	-0.1 h
November	15.0 h	15.4 h	-0.4 h
December	16.4 h	17.1 h	-0.7 h

Difference: Petrozavodsk minus Kostomuksha. Each figure links to that town's month page.

Season and midnight sun

Petrozavodsk has no civil darkness from May 29 to July 12, 45 nights in 2026, and its dark season, 4 or more evening hours of civil night, lasts 285 days. Kostomuksha has no civil darkness from May 15 to July 27, 74 nights in 2026, and its dark season, 4 or more evening hours of civil night, lasts 267 days.

Distance, cloud and time zones

The two towns are 363 km apart by great circle. In the dark months both average about 78% cloud in NASA POWER's 2001 to 2020 record. Petrozavodsk's best month by civil night times clear sky is January. Kostomuksha's best month by civil night times clear sky is January. Time zones: Europe/Moscow and Europe/Moscow.

For tonight, open the live pages for Petrozavodsk and Kostomuksha, which carry the live OVATION cell.

Questions

Is Petrozavodsk or Kostomuksha better for the northern lights?: Kostomuksha sits closer to the oval, at 61.1 degrees geomagnetic against 57.9. 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, Petrozavodsk or Kostomuksha?: Kostomuksha, with 17.1 hours of civil night on December 15 against 16.4 in Petrozavodsk.
What Kp do Petrozavodsk and Kostomuksha need?: By SWPC's rule of 66 degrees at Kp 0 and 2 degrees per step, Petrozavodsk needs about Kp 5 and Kostomuksha Kp 3 for the average oval edge to sit overhead.
When is it too light for aurora in Petrozavodsk and Kostomuksha?: Petrozavodsk: May 29 to July 12. Kostomuksha: May 15 to July 27.
Which is clearer, Petrozavodsk or Kostomuksha?: Petrozavodsk, with 78% mean cloud in the months with 4 hours or more of civil night against 78% in Kostomuksha (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.