Is Oulu or Ylivieska better for the northern lights?

Oulu sits closer to the oval, at 62.3 degrees geomagnetic against 61.5. 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, Oulu or Ylivieska?

Oulu, with 17.3 hours of civil night on December 15 against 17.0 in Ylivieska.

What Kp do Oulu and Ylivieska need?

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

When is it too light for aurora in Oulu and Ylivieska?

Oulu: May 13 to July 29. Ylivieska: May 17 to July 25.

Which is clearer, Oulu or Ylivieska?

Oulu, with 76% mean cloud in the months with 4 hours or more of civil night against 77% in Ylivieska (NASA POWER, 2001 to 2020).

Comparison

Oulu vs Ylivieska for the northern lights

Answer

Oulu sits 0.7 degrees higher on the IGRF-14 dipole, 62.3 against 61.5. By SWPC's oval-edge rule Oulu needs about Kp 2 for the average edge to sit overhead and Ylivieska Kp 3. On the map Oulu is also closer to the pole, by 0.9 degrees.

62.3° / 61.5°

dipole latitude

Side by side

Computed figures for both towns
Figure	Oulu	Ylivieska
Dipole latitude	62.3°	61.5°
Kp for the oval edge overhead	Kp 2	Kp 3
Civil night, December 15	17.3 h	17.0 h
Dark-season days	265	270
Nights with no civil darkness	78	70
Dark-month cloud, NASA POWER	76%	77%
Solar midnight, December 15	00:13	00:17

Oulu sits at 62.3 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. Ylivieska sits at 61.5 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 3.

Civil night month by month

On December 15 Oulu has 17.3 hours of civil night and Ylivieska 17.0. Across the 15th of each month, Oulu is darker in 4 months and Ylivieska in 4. The widest gap comes in May, when Ylivieska has 1.4 more hours.

Hours of civil night on the 15th of each month, 2026
Month	Oulu	Ylivieska	Difference
January	16.3 h	16.1 h	+0.2 h
February	13.5 h	13.5 h	+0.0 h
March	10.5 h	10.5 h	+0.0 h
April	6.6 h	6.8 h	-0.2 h
May	0.0 h	1.4 h	-1.4 h
June	0.0 h	0.0 h	+0.0 h
July	0.0 h	0.0 h	+0.0 h
August	4.9 h	5.3 h	-0.4 h
September	9.1 h	9.2 h	-0.1 h
October	12.5 h	12.4 h	+0.1 h
November	15.5 h	15.3 h	+0.2 h
December	17.3 h	17.0 h	+0.3 h

Difference: Oulu minus Ylivieska. Each figure links to that town's month page.

Season and midnight sun

Oulu has no civil darkness from May 13 to July 29, 78 nights in 2026, and its dark season, 4 or more evening hours of civil night, lasts 265 days. Ylivieska 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 112 km apart by great circle. In the dark months both average about 77% cloud in NASA POWER's 2001 to 2020 record. Oulu's best month by civil night times clear sky is January. Ylivieska's best month by civil night times clear sky is January. Time zones: Europe/Helsinki and Europe/Helsinki.

For tonight, open the live pages for Oulu and Ylivieska, which carry the live OVATION cell.

Questions

Is Oulu or Ylivieska better for the northern lights?: Oulu sits closer to the oval, at 62.3 degrees geomagnetic against 61.5. 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, Oulu or Ylivieska?: Oulu, with 17.3 hours of civil night on December 15 against 17.0 in Ylivieska.
What Kp do Oulu and Ylivieska need?: By SWPC's rule of 66 degrees at Kp 0 and 2 degrees per step, Oulu needs about Kp 2 and Ylivieska Kp 3 for the average oval edge to sit overhead.
When is it too light for aurora in Oulu and Ylivieska?: Oulu: May 13 to July 29. Ylivieska: May 17 to July 25.
Which is clearer, Oulu or Ylivieska?: Oulu, with 76% mean cloud in the months with 4 hours or more of civil night against 77% in Ylivieska (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.