Is Iisalmi or Kauhava better for the northern lights?

Kauhava sits closer to the oval, at 60.8 degrees geomagnetic against 60.6. 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, Iisalmi or Kauhava?

Iisalmi, with 16.8 hours of civil night on December 15 against 16.7 in Kauhava.

What Kp do Iisalmi and Kauhava need?

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

When is it too light for aurora in Iisalmi and Kauhava?

Iisalmi: May 20 to July 22. Kauhava: May 22 to July 20.

Which is clearer, Iisalmi or Kauhava?

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

Comparison

Iisalmi vs Kauhava for the northern lights

Answer

Kauhava sits 0.2 degrees higher on the IGRF-14 dipole, 60.8 against 60.6. By SWPC's oval-edge rule Kauhava needs about Kp 3 for the average edge to sit overhead and Iisalmi Kp 3. That reverses the map, where Iisalmi is 0.5 degrees closer to the pole.

60.6° / 60.8°

dipole latitude

Side by side

Computed figures for both towns
Figure	Iisalmi	Kauhava
Dipole latitude	60.6°	60.8°
Kp for the oval edge overhead	Kp 3	Kp 3
Civil night, December 15	16.8 h	16.7 h
Dark-season days	273	277
Nights with no civil darkness	64	60
Dark-month cloud, NASA POWER	77%	77%
Solar midnight, December 15	00:06	00:23

Iisalmi sits at 60.6 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. Kauhava sits at 60.8 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 3.

Civil night month by month

On December 15 Iisalmi has 16.8 hours of civil night and Kauhava 16.7. Across the 15th of each month, Iisalmi is darker in 2 months and Kauhava in 3. The widest gap comes in May, when Kauhava has 0.5 more hours.

Hours of civil night on the 15th of each month, 2026
Month	Iisalmi	Kauhava	Difference
January	16.0 h	15.9 h	+0.1 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	7.1 h	-0.1 h
May	2.1 h	2.6 h	-0.5 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	5.6 h	-0.1 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	16.7 h	+0.1 h

Difference: Iisalmi minus Kauhava. Each figure links to that town's month page.

Season and midnight sun

Iisalmi 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. Kauhava has no civil darkness from May 22 to July 20, 60 nights in 2026, and its dark season, 4 or more evening hours of civil night, lasts 277 days.

Distance, cloud and time zones

The two towns are 212 km apart by great circle. In the dark months both average about 77% cloud in NASA POWER's 2001 to 2020 record. Iisalmi's best month by civil night times clear sky is January. Kauhava's best month by civil night times clear sky is March. Time zones: Europe/Helsinki and Europe/Helsinki.

For tonight, open the live pages for Iisalmi and Kauhava, which carry the live OVATION cell.

Questions

Is Iisalmi or Kauhava better for the northern lights?: Kauhava sits closer to the oval, at 60.8 degrees geomagnetic against 60.6. 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, Iisalmi or Kauhava?: Iisalmi, with 16.8 hours of civil night on December 15 against 16.7 in Kauhava.
What Kp do Iisalmi and Kauhava need?: By SWPC's rule of 66 degrees at Kp 0 and 2 degrees per step, Iisalmi needs about Kp 3 and Kauhava Kp 3 for the average oval edge to sit overhead.
When is it too light for aurora in Iisalmi and Kauhava?: Iisalmi: May 20 to July 22. Kauhava: May 22 to July 20.
Which is clearer, Iisalmi or Kauhava?: Iisalmi, with 77% mean cloud in the months with 4 hours or more of civil night against 77% in Kauhava (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.