Can you see the northern lights in Keflavík in December?

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

How dark is Keflavík in December?

Keflavík averages 16.8 hours of civil night a night in December 2026, from 16 h 26 min on the 1st to 16 h 51 min on the last night.

How cloudy is Keflavík in December?

NASA POWER's 2001 to 2020 climatology gives Keflavík's 1 degree cell 82% 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 Keflavík?

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

Is December or January better in Keflavík?

By civil night times the clear share, December scores 3.1 hours at Keflavík and January 2.6. December comes out ahead.

Keflavík · December 2026

Northern lights in Keflavík in December 2026

Answer

December gives Keflavík 17.0 hours of civil night on the 15th, the darkest month of its year, under 82% mean cloud. 5% of December days since 1996 reached storm level, Kp 5.

16.8 h

civil night, average night

SunCalc for 64.00, -22.56; NASA POWER; GFZ Kp

December against the rest of the year

2.6

2.3

1.9

1.3

0.3

0.0

1.2

1.7

2.4

2.6

3.1

December cloud at Keflavík averages 82% in NASA POWER's 2001 to 2020 record, close to its yearly mean of 81%. May is Keflavík's clearest month at 77%. That makes December the best month of Keflavík's year by civil night times clear sky, 3.1 hours. Reykjanesbær, 1 km away, averages 85%, cloudier by 3 points.

Civil night at Keflavík starts December at 16 h 26 min and reaches 16 h 51 min by December 31 as the nights lengthen by 0.4 hours. SWPC's 10 PM to 2 AM window is fully dark on every night. True astronomical darkness, the sun 18 degrees down, lasts 12.7 hours on the 15th.

December night by night

December opens toward a new moon on Dec 9, with full moon on Dec 24, in Atlantic/Reykjavik dates. Keflavík gets 283 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 2 (4 h), Dec 3 (4 h), Dec 4 (4 h).

1
42% lit
8.8 h
2
32% lit
10.5 h
3
23% lit
12.2 h
4
15% lit
13.9 h
5
9% lit
15.7 h
6
4% lit
16.7 h
7
1% lit
16.7 h
8
0% lit
16.8 h
9
1% lit
16.8 h
New
10
4% lit
16.8 h
11
8% lit
16.9 h
12
13% lit
15.3 h
13
21% lit
13.5 h
14
29% lit
11.9 h
15
38% lit
10.3 h
16
48% lit
8.8 h
17
58% lit
7.2 h
18
68% lit
5.5 h
19
78% lit
3.6 h
20
87% lit
1.4 h
21
94% lit
0.0 h
22
98% lit
0.0 h
23
100% lit
0.0 h
24
99% lit
0.0 h
Full
25
94% lit
0.5 h
26
88% lit
2.7 h
27
79% lit
4.7 h
28
69% lit
6.5 h
29
58% lit
8.2 h
30
48% lit
9.8 h
31
38% lit
11.5 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 Keflavík, 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. Keflavík sits at 68.8 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 Iceland

Keflavík ranks 2nd in Iceland for civil night on December 15, behind Akureyri at 17.5 hours. Coming from November (15.3 hours at Keflavík), December adds darkness, and January brings shorter nights (16.1 hours on the 15th). The December solstice falls on December 21, 20:49 Keflavík time.

Civil night on December 15 and December cloud, month-page towns in Iceland
Town	Civil night	Cloud
Akureyri	17.5 h	81%
Keflavík	17.0 h	82%
Reykjavík	17.0 h	76%
Hafnarfjörður	17.0 h	76%
Reykjanesbær	17.0 h	85%

Darkness and moon, every night

Keflavík, 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	16 h 26 min	12 h 21 min	8 h 48 min	3 h 55 min	42%
Wed Dec 2	16 h 29 min	12 h 24 min	10 h 29 min	4 h	32%
Thu Dec 3	16 h 32 min	12 h 26 min	12 h 9 min	4 h	23%
Fri Dec 4	16 h 35 min	12 h 28 min	13 h 52 min	4 h	15%
Sat Dec 5	16 h 38 min	12 h 30 min	15 h 43 min	4 h	9%
Sun Dec 6	16 h 41 min	12 h 32 min	16 h 41 min	4 h	4%
Mon Dec 7	16 h 43 min	12 h 34 min	16 h 43 min	4 h	1%
Tue Dec 8	16 h 45 min	12 h 36 min	16 h 45 min	4 h	0%
Wed Dec 9	16 h 48 min	12 h 37 min	16 h 48 min	4 h	1%
Thu Dec 10	16 h 50 min	12 h 39 min	16 h 50 min	4 h	4%
Fri Dec 11	16 h 51 min	12 h 40 min	16 h 51 min	4 h	8%
Sat Dec 12	16 h 53 min	12 h 41 min	15 h 17 min	4 h	13%
Sun Dec 13	16 h 55 min	12 h 42 min	13 h 30 min	4 h	21%
Mon Dec 14	16 h 56 min	12 h 43 min	11 h 52 min	3 h 59 min	29%
Tue Dec 15	16 h 57 min	12 h 44 min	10 h 19 min	2 h 24 min	38%
Wed Dec 16	16 h 58 min	12 h 45 min	8 h 46 min	50 min	48%
Thu Dec 17	16 h 59 min	12 h 46 min	7 h 10 min	0 min	58%
Fri Dec 18	16 h 59 min	12 h 46 min	5 h 27 min	0 min	68%
Sat Dec 19	17 h	12 h 46 min	3 h 34 min	0 min	78%
Sun Dec 20	17 h	12 h 46 min	1 h 24 min	0 min	87%
Mon Dec 21	17 h	12 h 46 min	0 min	0 min	94%
Tue Dec 22	17 h	12 h 46 min	0 min	0 min	98%
Wed Dec 23	17 h	12 h 46 min	0 min	0 min	100%
Thu Dec 24	16 h 59 min	12 h 46 min	0 min	0 min	99%
Fri Dec 25	16 h 58 min	12 h 45 min	27 min	0 min	94%
Sat Dec 26	16 h 58 min	12 h 45 min	2 h 41 min	0 min	88%
Sun Dec 27	16 h 57 min	12 h 44 min	4 h 40 min	0 min	79%
Mon Dec 28	16 h 55 min	12 h 43 min	6 h 28 min	1 h 32 min	69%
Tue Dec 29	16 h 54 min	12 h 42 min	8 h 10 min	3 h 15 min	58%
Wed Dec 30	16 h 52 min	12 h 41 min	9 h 49 min	4 h	48%
Thu Dec 31	16 h 51 min	12 h 40 min	11 h 30 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 Keflavík in December?: On dark, clear nights with enough activity. 31 of 31 nights at Keflavík have civil darkness, and 5% of past December days reached Kp 5.
How dark is Keflavík in December?: Keflavík averages 16.8 hours of civil night a night in December 2026, from 16 h 26 min on the 1st to 16 h 51 min on the last night.
How cloudy is Keflavík in December?: NASA POWER's 2001 to 2020 climatology gives Keflavík's 1 degree cell 82% 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 Keflavík?: By darkness and moon alone, Dec 2, with 4 h of moon-free darkness inside 10 PM to 2 AM at Keflavík. Activity on that date will only be known hours ahead.
Is December or January better in Keflavík?: By civil night times the clear share, December scores 3.1 hours at Keflavík and January 2.6. December 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.