Is Helsinki or Espoo better for the northern lights?

Espoo sits closer to the oval, at 57.8 degrees geomagnetic against 57.7. 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, Helsinki or Espoo?

Espoo, with 16.1 hours of civil night on December 15 against 16.0 in Helsinki.

What Kp do Helsinki and Espoo need?

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

When is it too light for aurora in Helsinki and Espoo?

Helsinki: June 16 to June 25. Espoo: June 15 to June 26.

Which is clearer, Helsinki or Espoo?

Helsinki, with 74% mean cloud in the months with 4 hours or more of civil night against 74% in Espoo (NASA POWER, 2001 to 2020).

Comparison

Helsinki vs Espoo for the northern lights

Answer

Espoo sits 0.1 degrees higher on the IGRF-14 dipole, 57.8 against 57.7. By SWPC's oval-edge rule Espoo needs about Kp 5 for the average edge to sit overhead and Helsinki Kp 5. On the map Espoo is also closer to the pole, by 0.0 degrees.

57.7° / 57.8°

dipole latitude

Side by side

Computed figures for both towns
Figure	Helsinki	Espoo
Dipole latitude	57.7°	57.8°
Kp for the oval edge overhead	Kp 5	Kp 5
Civil night, December 15	16.0 h	16.1 h
Dark-season days	299	297
Nights with no civil darkness	10	12
Dark-month cloud, NASA POWER	74%	74%
Solar midnight, December 15	00:15	00:16

Helsinki sits at 57.7 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. Espoo sits at 57.8 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.

Civil night month by month

On December 15 Helsinki has 16.0 hours of civil night and Espoo 16.1. Across the 15th of each month, Helsinki is darker in 2 months and Espoo in 1. The widest gap comes in June, when Helsinki has 0.2 more hours.

Hours of civil night on the 15th of each month, 2026
Month	Helsinki	Espoo	Difference
January	15.4 h	15.4 h	+0.0 h
February	13.2 h	13.2 h	+0.0 h
March	10.7 h	10.7 h	+0.0 h
April	7.7 h	7.7 h	+0.0 h
May	4.4 h	4.3 h	+0.1 h
June	0.2 h	0.0 h	+0.2 h
July	2.9 h	2.9 h	+0.0 h
August	6.5 h	6.5 h	+0.0 h
September	9.6 h	9.6 h	+0.0 h
October	12.3 h	12.3 h	+0.0 h
November	14.7 h	14.7 h	+0.0 h
December	16.0 h	16.1 h	-0.1 h

Difference: Helsinki minus Espoo. Each figure links to that town's month page.

Season and midnight sun

Helsinki has no civil darkness from June 16 to June 25, 10 nights in 2026, and its dark season, 4 or more evening hours of civil night, lasts 299 days. Espoo has no civil darkness from June 15 to June 26, 12 nights in 2026, and its dark season, 4 or more evening hours of civil night, lasts 297 days.

Distance, cloud and time zones

The two towns are 16 km apart by great circle. In the dark months both average about 74% cloud in NASA POWER's 2001 to 2020 record. Helsinki's best month by civil night times clear sky is March. Espoo'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 Helsinki and Espoo, which carry the live OVATION cell.

Questions

Is Helsinki or Espoo better for the northern lights?: Espoo sits closer to the oval, at 57.8 degrees geomagnetic against 57.7. 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, Helsinki or Espoo?: Espoo, with 16.1 hours of civil night on December 15 against 16.0 in Helsinki.
What Kp do Helsinki and Espoo need?: By SWPC's rule of 66 degrees at Kp 0 and 2 degrees per step, Helsinki needs about Kp 5 and Espoo Kp 5 for the average oval edge to sit overhead.
When is it too light for aurora in Helsinki and Espoo?: Helsinki: June 16 to June 25. Espoo: June 15 to June 26.
Which is clearer, Helsinki or Espoo?: Helsinki, with 74% mean cloud in the months with 4 hours or more of civil night against 74% in Espoo (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.