Can you see the northern lights in Harstad in December?

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

How dark is Harstad in December?

Harstad averages 18.6 hours of civil night a night in December 2026, from 17 h 56 min on the 1st to 18 h 34 min on the last night.

How cloudy is Harstad in December?

NASA POWER's 2001 to 2020 climatology gives Harstad's 1 degree cell 83% mean cloud in December, against 81% for the whole year. It is an all-hours average, not a forecast.

What is the best night in December 2026 for aurora in Harstad?

By darkness and moon alone, Dec 3, with 4 h of moon-free darkness inside 10 PM to 2 AM at Harstad. Activity on that date will only be known hours ahead.

Is December or January better in Harstad?

By civil night times the clear share, December scores 3.2 hours at Harstad and January 3.5. January comes out ahead.

Harstad · December 2026

Northern lights in Harstad in December 2026

Answer

December gives Harstad 18.7 hours of civil night on the 15th, the darkest month of its year, under 83% mean cloud. 5% of December days since 1996 reached storm level, Kp 5.

18.6 h

civil night, average night

SunCalc for 68.80, 16.54; NASA POWER; GFZ Kp

December against the rest of the year

3.5

2.6

1.7

1.0

0.0

0.5

1.5

2.5

3.0

3.2

December cloud at Harstad averages 83% in NASA POWER's 2001 to 2020 record, 2 points cloudier than its yearly mean. July is Harstad's clearest month at 78%. By civil night times clear sky, December scores 3.2 hours at Harstad, 2nd of 12. Tromsø, 134 km away, averages 85%, cloudier by 2 points.

Civil night at Harstad starts December at 17 h 56 min and reaches 18 h 34 min by December 31 as the nights lengthen by 0.6 hours. SWPC's 10 PM to 2 AM window is fully dark on every night. True astronomical darkness, the sun 18 degrees down, lasts 13.2 hours on the 15th.

December night by night

December opens toward a new moon on Dec 9, with full moon on Dec 24, in Europe/Oslo dates. Harstad gets 312 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: Dec 3 (4 h), Dec 4 (4 h), Dec 5 (4 h).

1
43% lit
9.3 h
2
32% lit
11.2 h
3
23% lit
13.2 h
4
15% lit
15.3 h
5
9% lit
18.2 h
6
4% lit
18.3 h
7
1% lit
18.4 h
8
0% lit
18.4 h
9
1% lit
18.5 h
New
10
3% lit
18.5 h
11
8% lit
18.6 h
12
13% lit
18.6 h
13
20% lit
15.7 h
14
28% lit
13.6 h
15
37% lit
11.7 h
16
47% lit
9.9 h
17
58% lit
8.1 h
18
68% lit
6.1 h
19
78% lit
3.7 h
20
86% lit
0.0 h
21
93% lit
0.0 h
22
98% lit
0.0 h
23
100% lit
0.0 h
24
99% lit
0.0 h
Full
25
95% lit
0.0 h
26
88% lit
2.3 h
27
79% lit
4.9 h
28
69% lit
7.0 h
29
59% lit
8.9 h
30
48% lit
10.9 h
31
38% lit
12.9 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 Decembers

Quiet activity already puts the oval edge over Harstad, so storm days matter more: 44 of the 930 December days from 1996 to 2025 (5%) reached Kp 5, one of the three quietest months for that level. Harstad sits at 67.1 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 0.

December across Norway

Harstad ranks 3rd in Norway for civil night on December 15, behind Alta at 19.4 hours. Coming from November (16.4 hours at Harstad), December adds darkness, and January brings shorter nights (17.5 hours on the 15th). The December solstice falls on December 21, 21:49 Harstad time.

Civil night on December 15 and December cloud, month-page towns in Norway
Town	Civil night	Cloud
Alta	19.4 h	83%
Tromsø	19.2 h	85%
Harstad	18.7 h	83%
Bodø	18.0 h	84%
Mo i Rana	17.7 h	80%
Levanger	16.9 h	81%
Trondheim	16.8 h	81%
Stjørdalshalsen	16.8 h	81%
Kristiansund	16.7 h	85%
Ålesund	16.6 h	84%
Molde	16.6 h	84%
Hamar	16.2 h	77%

Darkness and moon, every night

Harstad, December 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
Tue Dec 1	17 h 56 min	12 h 42 min	9 h 17 min	2 h 3 min	43%
Wed Dec 2	18 h 1 min	12 h 46 min	11 h 13 min	3 h 57 min	32%
Thu Dec 3	18 h 5 min	12 h 48 min	13 h 11 min	4 h	23%
Fri Dec 4	18 h 10 min	12 h 51 min	15 h 19 min	4 h	15%
Sat Dec 5	18 h 14 min	12 h 54 min	18 h 14 min	4 h	9%
Sun Dec 6	18 h 18 min	12 h 56 min	18 h 18 min	4 h	4%
Mon Dec 7	18 h 22 min	12 h 59 min	18 h 22 min	4 h	1%
Tue Dec 8	18 h 25 min	13 h 1 min	18 h 25 min	4 h	0%
Wed Dec 9	18 h 29 min	13 h 3 min	18 h 29 min	4 h	1%
Thu Dec 10	18 h 32 min	13 h 5 min	18 h 32 min	4 h	3%
Fri Dec 11	18 h 35 min	13 h 7 min	18 h 35 min	4 h	8%
Sat Dec 12	18 h 37 min	13 h 8 min	18 h 37 min	4 h	13%
Sun Dec 13	18 h 40 min	13 h 10 min	15 h 44 min	4 h	20%
Mon Dec 14	18 h 42 min	13 h 11 min	13 h 33 min	4 h	28%
Tue Dec 15	18 h 43 min	13 h 12 min	11 h 40 min	4 h	37%
Wed Dec 16	18 h 45 min	13 h 13 min	9 h 53 min	2 h 40 min	47%
Thu Dec 17	18 h 46 min	13 h 14 min	8 h 3 min	50 min	58%
Fri Dec 18	18 h 47 min	13 h 14 min	6 h 4 min	0 min	68%
Sat Dec 19	18 h 48 min	13 h 15 min	3 h 43 min	0 min	78%
Sun Dec 20	18 h 48 min	13 h 15 min	0 min	0 min	86%
Mon Dec 21	18 h 48 min	13 h 15 min	0 min	0 min	93%
Tue Dec 22	18 h 48 min	13 h 15 min	0 min	0 min	98%
Wed Dec 23	18 h 48 min	13 h 15 min	0 min	0 min	100%
Thu Dec 24	18 h 47 min	13 h 14 min	0 min	0 min	99%
Fri Dec 25	18 h 46 min	13 h 14 min	0 min	0 min	95%
Sat Dec 26	18 h 45 min	13 h 13 min	2 h 19 min	0 min	88%
Sun Dec 27	18 h 43 min	13 h 12 min	4 h 52 min	0 min	79%
Mon Dec 28	18 h 41 min	13 h 11 min	6 h 59 min	0 min	69%
Tue Dec 29	18 h 39 min	13 h 9 min	8 h 57 min	1 h 33 min	59%
Wed Dec 30	18 h 37 min	13 h 8 min	10 h 52 min	3 h 30 min	48%
Thu Dec 31	18 h 34 min	13 h 6 min	12 h 54 min	4 h	38%

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

Questions

Can you see the northern lights in Harstad in December?: On dark, clear nights with enough activity. 31 of 31 nights at Harstad have civil darkness, and 5% of past December days reached Kp 5.
How dark is Harstad in December?: Harstad averages 18.6 hours of civil night a night in December 2026, from 17 h 56 min on the 1st to 18 h 34 min on the last night.
How cloudy is Harstad in December?: NASA POWER's 2001 to 2020 climatology gives Harstad's 1 degree cell 83% mean cloud in December, against 81% for the whole year. It is an all-hours average, not a forecast.
What is the best night in December 2026 for aurora in Harstad?: By darkness and moon alone, Dec 3, with 4 h of moon-free darkness inside 10 PM to 2 AM at Harstad. Activity on that date will only be known hours ahead.
Is December or January better in Harstad?: By civil night times the clear share, December scores 3.2 hours at Harstad and January 3.5. January 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.