Can you see the northern lights in Karhula in October?

On dark, clear nights with enough activity. 31 of 31 nights at Karhula have civil darkness, and 12% of past October days reached Kp 5.

How dark is Karhula in October?

Karhula averages 12.4 hours of civil night a night in October 2026, from 11 h 3 min on the 1st to 13 h 39 min on the last night.

How cloudy is Karhula in October?

NASA POWER's 2001 to 2020 climatology gives Karhula's 1 degree cell 80% mean cloud in October, against 73% for the whole year. It is an all-hours average, not a forecast.

What is the best night in October 2026 for aurora in Karhula?

By darkness and moon alone, Oct 6, with 4 h of moon-free darkness inside 10 PM to 2 AM at Karhula. Activity on that date will only be known hours ahead.

Is October or November better in Karhula?

By civil night times the clear share, October scores 2.5 hours at Karhula and November 1.9. October comes out ahead.

Karhula · October 2026

Northern lights in Karhula in October 2026

Answer

October gives Karhula 12.3 hours of civil night on the 15th, the 5th darkest of its 12 months, under 80% mean cloud. 12% of October days since 1996 reached Kp 5, enough for the oval edge to reach Karhula.

12.4 h

civil night, average night

SunCalc for 60.52, 26.93; NASA POWER; GFZ Kp

October against the rest of the year

2.6

3.0

2.4

1.6

0.0

1.0

2.3

3.1

2.5

1.9

2.3

October cloud at Karhula averages 80% in NASA POWER's 2001 to 2020 record, 7 points cloudier than its yearly mean. May is Karhula's clearest month at 62%. By civil night times clear sky, October scores 2.5 hours at Karhula, 5th of 12. Lahti, 86 km away, averages 78%, clearer by 2 points.

Civil night at Karhula starts October at 11 h 3 min and reaches 13 h 39 min by October 31 as the nights lengthen by 2.6 hours. SWPC's 10 PM to 2 AM window is fully dark on every night. True astronomical darkness, the sun 18 degrees down, lasts 9.0 hours on the 15th.

October night by night

October opens toward a new moon on Oct 10, with full moon on Oct 26, in Europe/Helsinki dates. Karhula gets 185 hours of civil night with the moon below the horizon across the month. The best of them for moon-free darkness inside 10 PM to 2 AM: Oct 6 (4 h), Oct 7 (4 h), Oct 8 (4 h).

1
69% lit
0.0 h
2
58% lit
0.4 h
3
47% lit
2.0 h
4
35% lit
3.9 h
5
25% lit
5.7 h
6
16% lit
7.5 h
7
9% lit
9.2 h
8
4% lit
10.8 h
9
1% lit
11.8 h
10
0% lit
11.9 h
New
11
2% lit
12.0 h
12
5% lit
12.1 h
13
10% lit
12.1 h
14
17% lit
12.2 h
15
25% lit
12.3 h
16
33% lit
12.3 h
17
43% lit
10.9 h
18
52% lit
9.3 h
19
62% lit
7.8 h
20
71% lit
6.3 h
21
79% lit
4.8 h
22
87% lit
3.4 h
23
93% lit
1.8 h
24
98% lit
0.2 h
25
100% lit
0.0 h
26
99% lit
0.0 h
Full
27
96% lit
0.0 h
28
90% lit
0.0 h
29
81% lit
0.0 h
30
72% lit
1.0 h
31
61% lit
2.8 h

Each cell is the night that starts on that date. Hours are civil-dark time with the moon below the horizon; the green rule scales with them. Green outline: new moon. Bone outline: full moon.

Activity in past Octobers

Karhula needs Kp 5 for the average oval edge to sit overhead. 116 of the 930 October days from 1996 to 2025 (12%) reached it in the GFZ Potsdam record, one of the three most active months for that level; storm days with Kp 5 or more made up 12%. Karhula 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.

October across Finland

Karhula ranks 20th in Finland for civil night on October 15, behind Oulu at 12.5 hours. Coming from September (9.6 hours at Karhula), October adds darkness, and the nights keep growing into November (14.8 hours on the 15th).

Civil night on October 15 and October cloud, month-page towns in Finland
Town	Civil night	Cloud
Oulu	12.5 h	81%
Rovaniemi	12.5 h	81%
Raahe	12.5 h	84%
Tornio	12.5 h	81%
Kemi	12.5 h	81%
Haukipudas	12.5 h	81%
Tampere	12.4 h	80%
Jyväskylä	12.4 h	82%
Kuopio	12.4 h	82%
Vaasa	12.4 h	77%
Seinäjoki	12.4 h	81%
Kokkola	12.4 h	83%
Karhula	12.3 h	80%

Darkness and moon, every night

Karhula, October 2026: each night from local noon to the next noon
Night	Civil	Astronomical	Moon-free dark	Moon-free, 10 PM to 2 AM	Moon lit
Thu Oct 1	11 h 3 min	7 h 39 min	0 min	0 min	69%
Fri Oct 2	11 h 9 min	7 h 46 min	24 min	0 min	58%
Sat Oct 3	11 h 14 min	7 h 52 min	2 h	0 min	47%
Sun Oct 4	11 h 20 min	7 h 58 min	3 h 52 min	1 h 14 min	35%
Mon Oct 5	11 h 25 min	8 h 4 min	5 h 44 min	3 h 3 min	25%
Tue Oct 6	11 h 31 min	8 h 10 min	7 h 31 min	4 h	16%
Wed Oct 7	11 h 36 min	8 h 16 min	9 h 11 min	4 h	9%
Thu Oct 8	11 h 42 min	8 h 22 min	10 h 49 min	4 h	4%
Fri Oct 9	11 h 47 min	8 h 28 min	11 h 47 min	4 h	1%
Sat Oct 10	11 h 52 min	8 h 34 min	11 h 52 min	4 h	0%
Sun Oct 11	11 h 58 min	8 h 40 min	11 h 58 min	4 h	2%
Mon Oct 12	12 h 3 min	8 h 45 min	12 h 3 min	4 h	5%
Tue Oct 13	12 h 8 min	8 h 51 min	12 h 8 min	4 h	10%
Wed Oct 14	12 h 13 min	8 h 56 min	12 h 13 min	4 h	17%
Thu Oct 15	12 h 19 min	9 h 2 min	12 h 19 min	4 h	25%
Fri Oct 16	12 h 24 min	9 h 7 min	12 h 16 min	4 h	33%
Sat Oct 17	12 h 29 min	9 h 13 min	10 h 54 min	4 h	43%
Sun Oct 18	12 h 34 min	9 h 18 min	9 h 21 min	4 h	52%
Mon Oct 19	12 h 39 min	9 h 23 min	7 h 49 min	2 h 31 min	62%
Tue Oct 20	12 h 45 min	9 h 28 min	6 h 19 min	59 min	71%
Wed Oct 21	12 h 50 min	9 h 34 min	4 h 50 min	0 min	79%
Thu Oct 22	12 h 55 min	9 h 39 min	3 h 21 min	0 min	87%
Fri Oct 23	13 h	9 h 44 min	1 h 50 min	0 min	93%
Sat Oct 24	13 h 5 min	9 h 49 min	14 min	0 min	98%
Sun Oct 25	13 h 10 min	9 h 53 min	0 min	0 min	100%
Mon Oct 26	13 h 15 min	9 h 58 min	0 min	0 min	99%
Tue Oct 27	13 h 20 min	10 h 3 min	0 min	0 min	96%
Wed Oct 28	13 h 25 min	10 h 8 min	0 min	0 min	90%
Thu Oct 29	13 h 30 min	10 h 12 min	0 min	0 min	81%
Fri Oct 30	13 h 35 min	10 h 17 min	59 min	0 min	72%
Sat Oct 31	13 h 39 min	10 h 22 min	2 h 49 min	0 min	61%

Moon lit: SunCalc illuminated fraction at the middle of the 10 PM to 2 AM window.

Questions

Can you see the northern lights in Karhula in October?: On dark, clear nights with enough activity. 31 of 31 nights at Karhula have civil darkness, and 12% of past October days reached Kp 5.
How dark is Karhula in October?: Karhula averages 12.4 hours of civil night a night in October 2026, from 11 h 3 min on the 1st to 13 h 39 min on the last night.
How cloudy is Karhula in October?: NASA POWER's 2001 to 2020 climatology gives Karhula's 1 degree cell 80% mean cloud in October, against 73% for the whole year. It is an all-hours average, not a forecast.
What is the best night in October 2026 for aurora in Karhula?: By darkness and moon alone, Oct 6, with 4 h of moon-free darkness inside 10 PM to 2 AM at Karhula. Activity on that date will only be known hours ahead.
Is October or November better in Karhula?: By civil night times the clear share, October scores 2.5 hours at Karhula and November 1.9. October comes out ahead.

Sources and verification

SunCalchttps://github.com/mourner/suncalc
NASA POWER climatologyhttps://power.larc.nasa.gov/docs/services/api/temporal/climatology/
GFZ Potsdam Kp indexhttps://kp.gfz.de/en/data
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.