Can you see the northern lights in Juneau in July?

On dark, clear nights with enough activity. 31 of 31 nights at Juneau have civil darkness, and 43% of past July days reached Kp 3.

How dark is Juneau in July?

Juneau averages 4.2 hours of civil night a night in July 2027, from 3 h 2 min on the 1st to 5 h 29 min on the last night.

How cloudy is Juneau in July?

NASA POWER's 2001 to 2020 climatology gives Juneau's 1 degree cell 81% mean cloud in July, against 79% for the whole year. It is an all-hours average, not a forecast.

What is the best night in July 2027 for aurora in Juneau?

By darkness and moon alone, Jul 31, with 3 h 40 min of moon-free darkness inside 10 PM to 2 AM at Juneau. Activity on that date will only be known hours ahead.

Is July or August better in Juneau?

By civil night times the clear share, July scores 0.8 hours at Juneau and August 1.4. August comes out ahead.

Juneau · July 2027

Northern lights in Juneau in July 2027

Answer

July gives Juneau 4.1 hours of civil night on the 15th, the 11th darkest of its 12 months, under 81% mean cloud. 43% of July days since 1996 reached Kp 3, enough for the oval edge to reach Juneau.

4.2 h

civil night, average night

SunCalc for 58.30, -134.42; NASA POWER; GFZ Kp

July against the rest of the year

3.0

3.3

2.6

2.0

1.3

0.5

0.8

1.4

1.9

2.3

3.0

3.1

July cloud at Juneau averages 81% in NASA POWER's 2001 to 2020 record, 2 points cloudier than its yearly mean. May is Juneau's clearest month at 74%. By civil night times clear sky, July scores 0.8 hours at Juneau, 11th of 12. Whitehorse, 271 km away, averages 74%, clearer by 7 points.

Civil night at Juneau starts July at 3 h 2 min and reaches 5 h 29 min by July 31 as the nights lengthen by 2.5 hours. No night keeps the 10 PM to 2 AM window fully dark at Juneau. The sun never reaches 18 degrees down, so Juneau gets no astronomical night in July.

July night by night

July opens toward a new moon on Jul 3, with full moon on Jul 18, in America/Juneau dates. Juneau gets 58 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: Jul 31 (3 h 40 min), Jul 30 (3 h 22 min), Jul 8 (2 h 41 min).

1
5% lit
2.1 h
2
1% lit
3.1 h
3
0% lit
3.1 h
New
4
2% lit
3.2 h
5
7% lit
3.3 h
6
15% lit
3.3 h
7
24% lit
3.4 h
8
34% lit
3.5 h
9
45% lit
3.5 h
10
56% lit
3.5 h
11
66% lit
3.4 h
12
75% lit
3.2 h
13
84% lit
3.0 h
14
90% lit
2.5 h
15
95% lit
1.6 h
16
98% lit
0.5 h
17
100% lit
0.0 h
18
100% lit
0.0 h
Full
19
98% lit
0.0 h
20
94% lit
0.0 h
21
88% lit
0.0 h
22
81% lit
0.0 h
23
73% lit
0.0 h
24
64% lit
0.0 h
25
54% lit
0.0 h
26
43% lit
0.2 h
27
33% lit
0.5 h
28
23% lit
1.0 h
29
14% lit
1.9 h
30
7% lit
3.4 h
31
2% lit
5.1 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 Julys

Juneau needs Kp 3 for the average oval edge to sit overhead. 403 of the 930 July days from 1996 to 2025 (43%) reached it in the GFZ Potsdam record, one of the three quietest months for that level; storm days with Kp 5 or more made up 9%. Juneau sits at 61.6 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 3.

July across United States

Juneau ranks 7th in United States for civil night on July 15, behind Buffalo at 7.8 hours. Coming from June (2.8 hours at Juneau), July adds darkness, and the nights keep growing into August (6.9 hours on the 15th).

Civil night on July 15 and July cloud, month-page towns in United States
Town	Civil night	Cloud
Buffalo	7.8 h	56%
Portland, Maine	7.6 h	55%
Minneapolis	7.4 h	46%
Duluth	7.2 h	51%
Fargo	7.1 h	48%
Seattle	7.0 h	47%
Juneau	4.1 h	81%
Anchorage	2.1 h	83%
Eagle River	2.0 h	83%
Fairbanks	0.0 h	77%

Darkness and moon, every night

Juneau, July 2027: each night from local noon to the next noon
Night	Civil	Moon-free dark	Moon-free, 10 PM to 2 AM	Moon lit
Thu Jul 1	3 h 2 min	2 h 9 min	2 h 9 min	5%
Fri Jul 2	3 h 5 min	3 h 5 min	2 h 31 min	1%
Sat Jul 3	3 h 9 min	3 h 9 min	2 h 32 min	0%
Sun Jul 4	3 h 12 min	3 h 12 min	2 h 34 min	2%
Mon Jul 5	3 h 16 min	3 h 16 min	2 h 35 min	7%
Tue Jul 6	3 h 20 min	3 h 20 min	2 h 37 min	15%
Wed Jul 7	3 h 24 min	3 h 24 min	2 h 39 min	24%
Thu Jul 8	3 h 28 min	3 h 28 min	2 h 41 min	34%
Fri Jul 9	3 h 33 min	3 h 30 min	2 h 40 min	45%
Sat Jul 10	3 h 37 min	3 h 27 min	2 h 35 min	56%
Sun Jul 11	3 h 42 min	3 h 22 min	2 h 28 min	66%
Mon Jul 12	3 h 47 min	3 h 13 min	2 h 16 min	75%
Tue Jul 13	3 h 52 min	2 h 57 min	1 h 57 min	84%
Wed Jul 14	3 h 56 min	2 h 27 min	1 h 25 min	90%
Thu Jul 15	4 h 2 min	1 h 37 min	32 min	95%
Fri Jul 16	4 h 7 min	28 min	0 min	98%
Sat Jul 17	4 h 12 min	0 min	0 min	100%
Sun Jul 18	4 h 17 min	0 min	0 min	100%
Mon Jul 19	4 h 22 min	0 min	0 min	98%
Tue Jul 20	4 h 28 min	0 min	0 min	94%
Wed Jul 21	4 h 33 min	0 min	0 min	88%
Thu Jul 22	4 h 39 min	0 min	0 min	81%
Fri Jul 23	4 h 44 min	0 min	0 min	73%
Sat Jul 24	4 h 50 min	0 min	0 min	64%
Sun Jul 25	4 h 55 min	0 min	0 min	54%
Mon Jul 26	5 h 1 min	11 min	11 min	43%
Tue Jul 27	5 h 7 min	29 min	29 min	33%
Wed Jul 28	5 h 12 min	1 h 1 min	1 h 1 min	23%
Thu Jul 29	5 h 18 min	1 h 56 min	1 h 56 min	14%
Fri Jul 30	5 h 24 min	3 h 22 min	3 h 22 min	7%
Sat Jul 31	5 h 29 min	5 h 8 min	3 h 40 min	2%

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

Questions

Can you see the northern lights in Juneau in July?: On dark, clear nights with enough activity. 31 of 31 nights at Juneau have civil darkness, and 43% of past July days reached Kp 3.
How dark is Juneau in July?: Juneau averages 4.2 hours of civil night a night in July 2027, from 3 h 2 min on the 1st to 5 h 29 min on the last night.
How cloudy is Juneau in July?: NASA POWER's 2001 to 2020 climatology gives Juneau's 1 degree cell 81% mean cloud in July, against 79% for the whole year. It is an all-hours average, not a forecast.
What is the best night in July 2027 for aurora in Juneau?: By darkness and moon alone, Jul 31, with 3 h 40 min of moon-free darkness inside 10 PM to 2 AM at Juneau. Activity on that date will only be known hours ahead.
Is July or August better in Juneau?: By civil night times the clear share, July scores 0.8 hours at Juneau and August 1.4. August 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.