Can you see the northern lights in Tromsø in August?

On dark, clear nights with enough activity. 16 of 31 nights at Tromsø have civil darkness, and 11% of past August days reached Kp 5.

How dark is Tromsø in August?

Tromsø averages 2.0 hours of civil night a night in August 2027, from 0 min on the 1st to 5 h 46 min on the last night.

How cloudy is Tromsø in August?

NASA POWER's 2001 to 2020 climatology gives Tromsø's 1 degree cell 79% mean cloud in August, against 82% for the whole year. It is an all-hours average, not a forecast.

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

By darkness and moon alone, Aug 30, with 4 h of moon-free darkness inside 10 PM to 2 AM at Tromsø. Activity on that date will only be known hours ahead.

Is August or September better in Tromsø?

By civil night times the clear share, August scores 0.1 hours at Tromsø and September 1.5. September comes out ahead.

Tromsø · August 2027

Northern lights in Tromsø in August 2027

Answer

August gives Tromsø 0.6 hours of civil night on the 15th, the 9th darkest of its 12 months, under 79% mean cloud. 11% of August days since 1996 reached storm level, Kp 5.

2.0 h

civil night, average night

SunCalc for 69.65, 18.96; NASA POWER; GFZ Kp

August against the rest of the year

3.0

2.4

1.5

0.9

0.0

0.1

1.5

2.2

2.7

2.9

August cloud at Tromsø averages 79% in NASA POWER's 2001 to 2020 record, 3 points clearer than its yearly mean. July is Tromsø's clearest month at 79%. By civil night times clear sky, August scores 0.1 hours at Tromsø, 9th of 12. Harstad, 134 km away, averages the same 79%.

Civil night at Tromsø starts August at 0 min and reaches 5 h 46 min by August 31 as the nights lengthen by 5.8 hours. 15 Tromsø nights this month have no civil darkness at all. The 10 PM to 2 AM window is fully dark on 2 of 31 nights. The sun never reaches 18 degrees down, so Tromsø 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 Europe/Oslo dates. Tromsø gets 15 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 30 (4 h), Aug 31 (4 h), Aug 29 (3 h 28 min).

1
0% lit
no night
2
0% lit
no night
New
3
3% lit
no night
4
9% lit
no night
5
17% lit
no night
6
26% lit
no night
7
37% lit
no night
8
47% lit
no night
9
57% lit
no night
10
67% lit
no night
11
76% lit
no night
12
84% lit
no night
13
90% lit
no night
14
95% lit
no night
15
98% lit
no night
16
100% lit
0.0 h
17
100% lit
0.0 h
Full
18
98% lit
0.0 h
19
94% lit
0.0 h
20
88% lit
0.0 h
21
81% lit
0.0 h
22
72% lit
0.0 h
23
63% lit
0.0 h
24
52% lit
0.0 h
25
41% lit
0.0 h
26
30% lit
0.0 h
27
20% lit
0.0 h
28
11% lit
0.0 h
29
5% lit
3.5 h
30
1% lit
5.6 h
31
0% lit
5.8 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 Tromsø, so storm days matter more: 99 of the 930 August days from 1996 to 2025 (11%) reached Kp 5, 5th of 12 months. Tromsø sits at 67.5 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 Norway

Tromsø ranks 19th in Norway for civil night on August 15, behind Kristiansand at 6.9 hours. Coming from July (0.0 hours at Tromsø), August adds darkness, and the nights keep growing into September (8.4 hours on the 15th).

Civil night on August 15 and August cloud, month-page towns in Norway
Town	Civil night	Cloud
Kristiansand	6.9 h	72%
Stavanger	6.8 h	79%
Haugesund	6.7 h	79%
Drammen	6.6 h	71%
Oslo	6.5 h	71%
Bergen	6.4 h	80%
Hamar	6.3 h	70%
Gjøvik	6.3 h	70%
Lillehammer	6.2 h	74%
Ålesund	5.8 h	83%
Molde	5.8 h	83%
Kristiansund	5.6 h	81%
Tromsø	0.6 h	79%

Darkness and moon, every night

Tromsø, 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	0 min	0 min	0 min	0%
Mon Aug 2	0 min	0 min	0 min	0%
Tue Aug 3	0 min	0 min	0 min	3%
Wed Aug 4	0 min	0 min	0 min	9%
Thu Aug 5	0 min	0 min	0 min	17%
Fri Aug 6	0 min	0 min	0 min	26%
Sat Aug 7	0 min	0 min	0 min	37%
Sun Aug 8	0 min	0 min	0 min	47%
Mon Aug 9	0 min	0 min	0 min	57%
Tue Aug 10	0 min	0 min	0 min	67%
Wed Aug 11	0 min	0 min	0 min	76%
Thu Aug 12	0 min	0 min	0 min	84%
Fri Aug 13	0 min	0 min	0 min	90%
Sat Aug 14	0 min	0 min	0 min	95%
Sun Aug 15	0 min	0 min	0 min	98%
Mon Aug 16	1 h 20 min	0 min	0 min	100%
Tue Aug 17	1 h 55 min	0 min	0 min	100%
Wed Aug 18	2 h 23 min	0 min	0 min	98%
Thu Aug 19	2 h 46 min	0 min	0 min	94%
Fri Aug 20	3 h 6 min	0 min	0 min	88%
Sat Aug 21	3 h 25 min	0 min	0 min	81%
Sun Aug 22	3 h 42 min	0 min	0 min	72%
Mon Aug 23	3 h 58 min	0 min	0 min	63%
Tue Aug 24	4 h 13 min	0 min	0 min	52%
Wed Aug 25	4 h 28 min	0 min	0 min	41%
Thu Aug 26	4 h 42 min	0 min	0 min	30%
Fri Aug 27	4 h 56 min	0 min	0 min	20%
Sat Aug 28	5 h 9 min	0 min	0 min	11%
Sun Aug 29	5 h 21 min	3 h 28 min	3 h 28 min	5%
Mon Aug 30	5 h 34 min	5 h 34 min	4 h	1%
Tue Aug 31	5 h 46 min	5 h 46 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 Tromsø in August?: On dark, clear nights with enough activity. 16 of 31 nights at Tromsø have civil darkness, and 11% of past August days reached Kp 5.
How dark is Tromsø in August?: Tromsø averages 2.0 hours of civil night a night in August 2027, from 0 min on the 1st to 5 h 46 min on the last night.
How cloudy is Tromsø in August?: NASA POWER's 2001 to 2020 climatology gives Tromsø's 1 degree cell 79% mean cloud in August, against 82% for the whole year. It is an all-hours average, not a forecast.
What is the best night in August 2027 for aurora in Tromsø?: By darkness and moon alone, Aug 30, with 4 h of moon-free darkness inside 10 PM to 2 AM at Tromsø. Activity on that date will only be known hours ahead.
Is August or September better in Tromsø?: By civil night times the clear share, August scores 0.1 hours at Tromsø and September 1.5. 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.