Is Tallinn or Espoo better for the northern lights?

Espoo sits closer to the oval, at 57.8 degrees geomagnetic against 57.1. 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, Tallinn or Espoo?

Espoo, with 16.1 hours of civil night on December 15 against 15.9 in Tallinn.

What Kp do Tallinn and Espoo need?

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

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

Tallinn: never, every night has civil darkness. Espoo: June 15 to June 26.

Which is clearer, Tallinn or Espoo?

Espoo, with 74% mean cloud in the months with 4 hours or more of civil night against 75% in Tallinn (NASA POWER, 2001 to 2020).

Comparison

Tallinn vs Espoo for the northern lights

Answer

Espoo sits 0.7 degrees higher on the IGRF-14 dipole, 57.8 against 57.1. By SWPC's oval-edge rule Espoo needs about Kp 5 for the average edge to sit overhead and Tallinn Kp 5. On the map Espoo is also closer to the pole, by 0.8 degrees.

57.1° / 57.8°

dipole latitude

Side by side

Computed figures for both towns
Figure	Tallinn	Espoo
Dipole latitude	57.1°	57.8°
Kp for the oval edge overhead	Kp 5	Kp 5
Civil night, December 15	15.9 h	16.1 h
Dark-season days	305	297
Nights with no civil darkness	0	12
Dark-month cloud, NASA POWER	75%	74%
Solar midnight, December 15	00:16	00:16

Tallinn sits at 57.1 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 Tallinn has 15.9 hours of civil night and Espoo 16.1. Across the 15th of each month, Tallinn is darker in 6 months and Espoo in 4. The widest gap comes in June, when Tallinn has 1.8 more hours.

Hours of civil night on the 15th of each month, 2026
Month	Tallinn	Espoo	Difference
January	15.3 h	15.4 h	-0.1 h
February	13.1 h	13.2 h	-0.1 h
March	10.7 h	10.7 h	+0.0 h
April	7.8 h	7.7 h	+0.1 h
May	4.7 h	4.3 h	+0.4 h
June	1.8 h	0.0 h	+1.8 h
July	3.4 h	2.9 h	+0.5 h
August	6.7 h	6.5 h	+0.2 h
September	9.7 h	9.6 h	+0.1 h
October	12.3 h	12.3 h	+0.0 h
November	14.6 h	14.7 h	-0.1 h
December	15.9 h	16.1 h	-0.2 h

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

Season and midnight sun

Tallinn has some civil darkness every night of 2026, and its dark season, 4 or more evening hours of civil night, lasts 305 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 86 km apart by great circle. In the dark months both average about 74% cloud in NASA POWER's 2001 to 2020 record. Tallinn'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/Tallinn and Europe/Helsinki.

For tonight, open the live pages for Tallinn and Espoo, which carry the live OVATION cell.

Questions

Is Tallinn or Espoo better for the northern lights?: Espoo sits closer to the oval, at 57.8 degrees geomagnetic against 57.1. 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, Tallinn or Espoo?: Espoo, with 16.1 hours of civil night on December 15 against 15.9 in Tallinn.
What Kp do Tallinn and Espoo need?: By SWPC's rule of 66 degrees at Kp 0 and 2 degrees per step, Tallinn needs about Kp 5 and Espoo Kp 5 for the average oval edge to sit overhead.
When is it too light for aurora in Tallinn and Espoo?: Tallinn: never, every night has civil darkness. Espoo: June 15 to June 26.
Which is clearer, Tallinn or Espoo?: Espoo, with 74% mean cloud in the months with 4 hours or more of civil night against 75% in Tallinn (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.