Can you see the northern lights in Waltham in October?

On dark, clear nights with enough activity. 31 of 31 nights at Waltham have civil darkness, and 1% of past October days reached Kp 8.

How dark is Waltham in October?

Waltham averages 11.9 hours of civil night a night in October 2026, from 11 h 16 min on the 1st to 12 h 35 min on the last night.

How cloudy is Waltham in October?

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

What is the best night in October 2026 for aurora in Waltham?

By darkness and moon alone, Oct 5, 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 October or November better in Waltham?

By civil night times the clear share, October scores 4.9 hours at Waltham and November 5.2. November comes out ahead.

Waltham · October 2026

Northern lights in Waltham in October 2026

Answer

October gives Waltham 11.9 hours of civil night on the 15th, the 5th darkest of its 12 months, under 59% mean cloud. 1% of October days since 1996 reached Kp 8, enough for the oval edge to reach Waltham.

11.9 h

civil night, average night

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

October 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

October cloud at Waltham averages 59% in NASA POWER's 2001 to 2020 record, close to its yearly mean of 59%. September is Waltham's clearest month at 51%. By civil night times clear sky, October scores 4.9 hours at Waltham, 5th of 12. Portland, Maine, 163 km away, averages the same 59%.

Civil night at Waltham starts October at 11 h 16 min and reaches 12 h 35 min by October 31 as the nights lengthen by 1.3 hours. SWPC's 10 PM to 2 AM window is fully dark on every night. True astronomical darkness, the sun 18 degrees down, lasts 9.7 hours on the 15th.

October night by night

October opens toward a new moon on Oct 10, with full moon on Oct 26, in America/New_York dates. Waltham gets 184 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: Oct 5 (4 h), Oct 6 (4 h), Oct 7 (4 h).

1
66% lit
2.4 h
2
55% lit
3.5 h
3
43% lit
4.7 h
4
32% lit
6.0 h
5
22% lit
7.3 h
6
14% lit
8.6 h
7
7% lit
9.8 h
8
3% lit
11.0 h
9
0% lit
11.6 h
10
0% lit
11.7 h
New
11
3% lit
11.7 h
12
7% lit
11.7 h
13
12% lit
11.2 h
14
19% lit
10.6 h
15
27% lit
9.8 h
16
36% lit
8.9 h
17
45% lit
7.9 h
18
55% lit
6.9 h
19
64% lit
5.8 h
20
73% lit
4.7 h
21
82% lit
3.6 h
22
89% lit
2.5 h
23
95% lit
1.4 h
24
99% lit
0.1 h
25
100% lit
0.0 h
26
98% lit
0.0 h
Full
27
94% lit
0.1 h
28
88% lit
1.0 h
29
79% lit
2.0 h
30
69% lit
3.3 h
31
58% lit
4.5 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 Octobers

Waltham needs Kp 8 for the average oval edge to sit overhead. 6 of the 930 October days from 1996 to 2025 (1%) reached it in the GFZ Potsdam record, one of the three most active months for that level; storm days with Kp 5 or more made up 12%. 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.

October across United States

Waltham ranks 9th in United States for civil night on October 15, behind Fairbanks at 12.5 hours. Coming from September (10.5 hours at Waltham), October adds darkness, and the nights keep growing into November (13.1 hours on the 15th).

Civil night on October 15 and October cloud, month-page towns in United States
Town	Civil night	Cloud
Fairbanks	12.5 h	77%
Anchorage	12.4 h	77%
Eagle River	12.4 h	77%
Juneau	12.3 h	81%
Seattle	12.0 h	68%
Minneapolis	12.0 h	59%
Duluth	12.0 h	64%
Fargo	12.0 h	60%
Waltham	11.9 h	59%
Buffalo	11.9 h	70%
Portland, Maine	11.9 h	59%

Darkness and moon, every night

Waltham, October 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
Thu Oct 1	11 h 16 min	9 h 5 min	2 h 24 min	0 min	66%
Fri Oct 2	11 h 18 min	9 h 8 min	3 h 29 min	24 min	55%
Sat Oct 3	11 h 21 min	9 h 11 min	4 h 44 min	1 h 37 min	43%
Sun Oct 4	11 h 24 min	9 h 13 min	6 h 2 min	2 h 53 min	32%
Mon Oct 5	11 h 27 min	9 h 16 min	7 h 20 min	4 h	22%
Tue Oct 6	11 h 30 min	9 h 19 min	8 h 35 min	4 h	14%
Wed Oct 7	11 h 32 min	9 h 22 min	9 h 48 min	4 h	7%
Thu Oct 8	11 h 35 min	9 h 25 min	11 h	4 h	3%
Fri Oct 9	11 h 38 min	9 h 28 min	11 h 38 min	4 h	0%
Sat Oct 10	11 h 41 min	9 h 31 min	11 h 41 min	4 h	0%
Sun Oct 11	11 h 43 min	9 h 33 min	11 h 43 min	4 h	3%
Mon Oct 12	11 h 46 min	9 h 36 min	11 h 43 min	4 h	7%
Tue Oct 13	11 h 49 min	9 h 39 min	11 h 12 min	4 h	12%
Wed Oct 14	11 h 52 min	9 h 41 min	10 h 33 min	4 h	19%
Thu Oct 15	11 h 54 min	9 h 44 min	9 h 47 min	4 h	27%
Fri Oct 16	11 h 57 min	9 h 47 min	8 h 54 min	4 h	36%
Sat Oct 17	12 h	9 h 49 min	7 h 55 min	3 h 24 min	45%
Sun Oct 18	12 h 2 min	9 h 52 min	6 h 52 min	2 h 21 min	55%
Mon Oct 19	12 h 5 min	9 h 55 min	5 h 48 min	1 h 15 min	64%
Tue Oct 20	12 h 8 min	9 h 57 min	4 h 43 min	9 min	73%
Wed Oct 21	12 h 10 min	10 h	3 h 37 min	0 min	82%
Thu Oct 22	12 h 13 min	10 h 2 min	2 h 31 min	0 min	89%
Fri Oct 23	12 h 15 min	10 h 5 min	1 h 21 min	0 min	95%
Sat Oct 24	12 h 18 min	10 h 7 min	9 min	0 min	99%
Sun Oct 25	12 h 20 min	10 h 10 min	0 min	0 min	100%
Mon Oct 26	12 h 23 min	10 h 12 min	0 min	0 min	98%
Tue Oct 27	12 h 25 min	10 h 14 min	7 min	0 min	94%
Wed Oct 28	12 h 28 min	10 h 17 min	58 min	0 min	88%
Thu Oct 29	12 h 30 min	10 h 19 min	2 h 2 min	0 min	79%
Fri Oct 30	12 h 33 min	10 h 21 min	3 h 15 min	0 min	69%
Sat Oct 31	12 h 35 min	10 h 24 min	4 h 33 min	44 min	58%

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 October?: On dark, clear nights with enough activity. 31 of 31 nights at Waltham have civil darkness, and 1% of past October days reached Kp 8.
How dark is Waltham in October?: Waltham averages 11.9 hours of civil night a night in October 2026, from 11 h 16 min on the 1st to 12 h 35 min on the last night.
How cloudy is Waltham in October?: NASA POWER's 2001 to 2020 climatology gives Waltham's 1 degree cell 59% mean cloud in October, against 59% for the whole year. It is an all-hours average, not a forecast.
What is the best night in October 2026 for aurora in Waltham?: By darkness and moon alone, Oct 5, 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 October or November better in Waltham?: By civil night times the clear share, October scores 4.9 hours at Waltham and November 5.2. November 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.