Can you see the northern lights in Keflavík in August?

On dark, clear nights with enough activity. 31 of 31 nights at Keflavík have civil darkness, and 11% of past August days reached Kp 5.

How dark is Keflavík in August?

Keflavík averages 5.3 hours of civil night a night in August 2027, from 2 h 51 min on the 1st to 7 h 25 min on the last night.

How cloudy is Keflavík in August?

NASA POWER's 2001 to 2020 climatology gives Keflavík's 1 degree cell 78% mean cloud in August, against 81% for the whole year. It is an all-hours average, not a forecast.

What is the best night in August 2027 for aurora in Keflavík?

By darkness and moon alone, Aug 29, 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 August or September better in Keflavík?

By civil night times the clear share, August scores 1.2 hours at Keflavík and September 1.7. September comes out ahead.

Keflavík · August 2027

Northern lights in Keflavík in August 2027

Answer

August gives Keflavík 5.3 hours of civil night on the 15th, the 9th darkest of its 12 months, under 78% mean cloud. 11% of August days since 1996 reached storm level, Kp 5.

5.3 h

civil night, average night

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

August 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

August cloud at Keflavík averages 78% in NASA POWER's 2001 to 2020 record, 3 points clearer than its yearly mean. May is Keflavík's clearest month at 77%. By civil night times clear sky, August scores 1.2 hours at Keflavík, 9th of 12. Reykjanesbær, 1 km away, averages 81%, cloudier by 3 points.

Civil night at Keflavík starts August at 2 h 51 min and reaches 7 h 25 min by August 31 as the nights lengthen by 4.6 hours. The 10 PM to 2 AM window is fully dark on 4 of 31 nights. The sun never reaches 18 degrees down, so Keflavík gets no astronomical night in August.

August night by night

August opens toward a new moon on Aug 2 and Aug 31, with full moon on Aug 17, in Atlantic/Reykjavik dates. Keflavík gets 78 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: Aug 29 (4 h), Aug 30 (4 h), Aug 31 (4 h).

1
0% lit
2.9 h
2
1% lit
3.1 h
New
3
4% lit
3.3 h
4
10% lit
3.5 h
5
18% lit
3.6 h
6
27% lit
3.8 h
7
38% lit
4.0 h
8
48% lit
4.2 h
9
58% lit
4.3 h
10
68% lit
4.5 h
11
77% lit
4.7 h
12
84% lit
4.8 h
13
90% lit
4.0 h
14
95% lit
2.0 h
15
98% lit
0.3 h
16
100% lit
0.0 h
17
100% lit
0.0 h
Full
18
97% lit
0.0 h
19
93% lit
0.0 h
20
88% lit
0.0 h
21
80% lit
0.0 h
22
72% lit
0.0 h
23
62% lit
0.0 h
24
51% lit
0.0 h
25
40% lit
0.0 h
26
29% lit
0.0 h
27
19% lit
1.1 h
28
11% lit
3.5 h
29
4% lit
5.8 h
30
1% lit
7.3 h
31
0% lit
7.4 h
New

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 Augusts

Quiet activity already puts the oval edge over Keflavík, so storm days matter more: 99 of the 930 August days from 1996 to 2025 (11%) reached Kp 5, 5th of 12 months. 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.

August across Iceland

No month-page town in Iceland has more civil night on August 15 than Keflavík; the national median is 5.3 hours. Coming from July (0.0 hours at Keflavík), August adds darkness, and the nights keep growing into September (9.2 hours on the 15th).

Civil night on August 15 and August cloud, month-page towns in Iceland
Town	Civil night	Cloud
Keflavík	5.3 h	78%
Reykjavík	5.3 h	79%
Hafnarfjörður	5.3 h	79%
Reykjanesbær	5.3 h	81%
Akureyri	4.6 h	82%

Darkness and moon, every night

Keflavík, August 2027: each night from local noon to the next noon
Night	Civil	Moon-free dark	Moon-free, 10 PM to 2 AM	Moon lit
Sun Aug 1	2 h 51 min	2 h 51 min	1 h 49 min	0%
Mon Aug 2	3 h 4 min	3 h 4 min	1 h 55 min	1%
Tue Aug 3	3 h 16 min	3 h 16 min	2 h 1 min	4%
Wed Aug 4	3 h 28 min	3 h 28 min	2 h 7 min	10%
Thu Aug 5	3 h 39 min	3 h 39 min	2 h 13 min	18%
Fri Aug 6	3 h 50 min	3 h 50 min	2 h 18 min	27%
Sat Aug 7	4 h	4 h	2 h 24 min	38%
Sun Aug 8	4 h 11 min	4 h 11 min	2 h 29 min	48%
Mon Aug 9	4 h 21 min	4 h 21 min	2 h 34 min	58%
Tue Aug 10	4 h 30 min	4 h 30 min	2 h 39 min	68%
Wed Aug 11	4 h 40 min	4 h 40 min	2 h 44 min	77%
Thu Aug 12	4 h 49 min	4 h 49 min	2 h 49 min	84%
Fri Aug 13	4 h 58 min	4 h 2 min	1 h 57 min	90%
Sat Aug 14	5 h 8 min	1 h 58 min	0 min	95%
Sun Aug 15	5 h 16 min	16 min	0 min	98%
Mon Aug 16	5 h 25 min	0 min	0 min	100%
Tue Aug 17	5 h 34 min	0 min	0 min	100%
Wed Aug 18	5 h 42 min	0 min	0 min	97%
Thu Aug 19	5 h 51 min	0 min	0 min	93%
Fri Aug 20	5 h 59 min	0 min	0 min	88%
Sat Aug 21	6 h 7 min	0 min	0 min	80%
Sun Aug 22	6 h 16 min	0 min	0 min	72%
Mon Aug 23	6 h 24 min	0 min	0 min	62%
Tue Aug 24	6 h 32 min	0 min	0 min	51%
Wed Aug 25	6 h 39 min	0 min	0 min	40%
Thu Aug 26	6 h 47 min	0 min	0 min	29%
Fri Aug 27	6 h 55 min	1 h 3 min	1 h 3 min	19%
Sat Aug 28	7 h 3 min	3 h 32 min	3 h 32 min	11%
Sun Aug 29	7 h 10 min	5 h 47 min	4 h	4%
Mon Aug 30	7 h 18 min	7 h 18 min	4 h	1%
Tue Aug 31	7 h 25 min	7 h 25 min	4 h	0%

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 August?: On dark, clear nights with enough activity. 31 of 31 nights at Keflavík have civil darkness, and 11% of past August days reached Kp 5.
How dark is Keflavík in August?: Keflavík averages 5.3 hours of civil night a night in August 2027, from 2 h 51 min on the 1st to 7 h 25 min on the last night.
How cloudy is Keflavík in August?: NASA POWER's 2001 to 2020 climatology gives Keflavík's 1 degree cell 78% mean cloud in August, against 81% for the whole year. It is an all-hours average, not a forecast.
What is the best night in August 2027 for aurora in Keflavík?: By darkness and moon alone, Aug 29, 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 August or September better in Keflavík?: By civil night times the clear share, August scores 1.2 hours at Keflavík and September 1.7. September 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.