Can you see the northern lights in Waltham in June?

On dark, clear nights with enough activity. 30 of 30 nights at Waltham have civil darkness, and 0% of past June days reached Kp 8.

How dark is Waltham in June?

Waltham averages 7.5 hours of civil night a night in June 2027, from 7 h 40 min on the 1st to 7 h 30 min on the last night.

How cloudy is Waltham in June?

NASA POWER's 2001 to 2020 climatology gives Waltham's 1 degree cell 62% mean cloud in June, against 59% for the whole year. It is an all-hours average, not a forecast.

What is the best night in June 2027 for aurora in Waltham?

By darkness and moon alone, Jun 1, with 4 h of moon-free darkness inside 10 PM to 2 AM at Waltham. Activity on that date will only be known hours ahead.

Is June or July better in Waltham?

By civil night times the clear share, June scores 2.9 hours at Waltham and July 3.5. July comes out ahead.

Waltham · June 2027

Northern lights in Waltham in June 2027

Answer

June gives Waltham 7.5 hours of civil night on the 15th, the lightest month of its year, under 62% mean cloud. 0% of June days since 1996 reached Kp 8, enough for the oval edge to reach Waltham.

7.5 h

civil night, average night

SunCalc for 42.38, -71.24; NASA POWER; GFZ Kp

June against the rest of the year

5.1

4.8

4.3

3.7

3.0

2.9

3.5

4.2

5.1

4.9

5.2

5.1

June cloud at Waltham averages 62% in NASA POWER's 2001 to 2020 record, 3 points cloudier than its yearly mean. September is Waltham's clearest month at 51%. By civil night times clear sky, June scores 2.9 hours at Waltham, 12th of 12. Portland, Maine, 163 km away, averages the same 62%.

Civil night at Waltham starts June at 7 h 40 min and reaches 7 h 30 min by June 30, 0.2 hours shorter. SWPC's 10 PM to 2 AM window is fully dark on every night. True astronomical darkness, the sun 18 degrees down, lasts 4.1 hours on the 15th.

June night by night

June opens toward a new moon on Jun 4, with full moon on Jun 18, in America/New_York dates. Waltham gets 106 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: Jun 1 (4 h), Jun 2 (4 h), Jun 3 (4 h).

1
9% lit
6.3 h
2
4% lit
6.8 h
3
1% lit
7.6 h
4
0% lit
7.6 h
New
5
3% lit
6.8 h
6
8% lit
5.9 h
7
16% lit
5.2 h
8
25% lit
4.7 h
9
36% lit
4.2 h
10
47% lit
3.8 h
11
58% lit
3.4 h
12
68% lit
3.0 h
13
78% lit
2.6 h
14
86% lit
2.2 h
15
92% lit
1.6 h
16
97% lit
1.0 h
17
99% lit
0.2 h
18
100% lit
0.0 h
Full
19
99% lit
0.3 h
20
96% lit
1.0 h
21
91% lit
1.4 h
22
85% lit
1.9 h
23
78% lit
2.2 h
24
70% lit
2.6 h
25
60% lit
2.9 h
26
51% lit
3.2 h
27
40% lit
3.6 h
28
30% lit
4.0 h
29
21% lit
4.5 h
30
12% lit
5.2 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 Junes

Waltham needs Kp 8 for the average oval edge to sit overhead. 1 of the 900 June days from 1996 to 2025 (0%) 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 8%. Waltham sits at 51.6 degrees geomagnetic. The lowest NOAA storm level whose typical viewing latitude reaches it is G3 (Kp = 7). By SWPC's rule the average oval edge is overhead only at Kp 8.

June across United States

No month-page town in United States has more civil night on June 15 than Waltham; the national median is 6.7 hours. Coming from May (8.2 hours at Waltham), June loses darkness, and the nights keep growing into July (7.8 hours on the 15th). The June solstice falls on June 21, 10:07 Waltham time.

Civil night on June 15 and June cloud, month-page towns in United States
Town	Civil night	Cloud
Waltham	7.5 h	62%
Buffalo	7.4 h	61%
Portland, Maine	7.3 h	62%
Minneapolis	7.0 h	58%
Duluth	6.7 h	61%
Fargo	6.7 h	57%
Seattle	6.5 h	68%
Juneau	2.8 h	81%
Anchorage	0.0 h	81%
Fairbanks	0.0 h	73%
Eagle River	0.0 h	81%

Darkness and moon, every night

Waltham, June 2027: 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 Jun 1	7 h 40 min	4 h 27 min	6 h 15 min	4 h	9%
Wed Jun 2	7 h 39 min	4 h 25 min	6 h 50 min	4 h	4%
Thu Jun 3	7 h 38 min	4 h 23 min	7 h 36 min	4 h	1%
Fri Jun 4	7 h 37 min	4 h 20 min	7 h 37 min	4 h	0%
Sat Jun 5	7 h 35 min	4 h 18 min	6 h 46 min	4 h	3%
Sun Jun 6	7 h 34 min	4 h 17 min	5 h 54 min	3 h 23 min	8%
Mon Jun 7	7 h 33 min	4 h 15 min	5 h 12 min	2 h 42 min	16%
Tue Jun 8	7 h 32 min	4 h 13 min	4 h 40 min	2 h 9 min	25%
Wed Jun 9	7 h 31 min	4 h 11 min	4 h 12 min	1 h 42 min	36%
Thu Jun 10	7 h 31 min	4 h 10 min	3 h 48 min	1 h 19 min	47%
Fri Jun 11	7 h 30 min	4 h 9 min	3 h 26 min	56 min	58%
Sat Jun 12	7 h 29 min	4 h 7 min	3 h 3 min	34 min	68%
Sun Jun 13	7 h 29 min	4 h 6 min	2 h 39 min	9 min	78%
Mon Jun 14	7 h 28 min	4 h 5 min	2 h 11 min	0 min	86%
Tue Jun 15	7 h 28 min	4 h 5 min	1 h 38 min	0 min	92%
Wed Jun 16	7 h 27 min	4 h 4 min	59 min	0 min	97%
Thu Jun 17	7 h 27 min	4 h 3 min	13 min	0 min	99%
Fri Jun 18	7 h 27 min	4 h 3 min	0 min	0 min	100%
Sat Jun 19	7 h 27 min	4 h 3 min	21 min	0 min	99%
Sun Jun 20	7 h 26 min	4 h 3 min	58 min	1 min	96%
Mon Jun 21	7 h 26 min	4 h 3 min	1 h 27 min	31 min	91%
Tue Jun 22	7 h 27 min	4 h 3 min	1 h 53 min	56 min	85%
Wed Jun 23	7 h 27 min	4 h 3 min	2 h 14 min	1 h 18 min	78%
Thu Jun 24	7 h 27 min	4 h 3 min	2 h 34 min	1 h 38 min	70%
Fri Jun 25	7 h 27 min	4 h 4 min	2 h 54 min	1 h 58 min	60%
Sat Jun 26	7 h 28 min	4 h 5 min	3 h 13 min	2 h 18 min	51%
Sun Jun 27	7 h 28 min	4 h 6 min	3 h 35 min	2 h 40 min	40%
Mon Jun 28	7 h 29 min	4 h 7 min	4 h 1 min	3 h 5 min	30%
Tue Jun 29	7 h 29 min	4 h 8 min	4 h 32 min	3 h 36 min	21%
Wed Jun 30	7 h 30 min	4 h 9 min	5 h 13 min	4 h	12%

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

Questions

Can you see the northern lights in Waltham in June?: On dark, clear nights with enough activity. 30 of 30 nights at Waltham have civil darkness, and 0% of past June days reached Kp 8.
How dark is Waltham in June?: Waltham averages 7.5 hours of civil night a night in June 2027, from 7 h 40 min on the 1st to 7 h 30 min on the last night.
How cloudy is Waltham in June?: NASA POWER's 2001 to 2020 climatology gives Waltham's 1 degree cell 62% mean cloud in June, against 59% for the whole year. It is an all-hours average, not a forecast.
What is the best night in June 2027 for aurora in Waltham?: By darkness and moon alone, Jun 1, with 4 h of moon-free darkness inside 10 PM to 2 AM at Waltham. Activity on that date will only be known hours ahead.
Is June or July better in Waltham?: By civil night times the clear share, June scores 2.9 hours at Waltham and July 3.5. July 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.