Can you see the northern lights in Idaho Falls in December?

On dark, clear nights with enough activity. 31 of 31 nights at Idaho Falls have civil darkness, and 0% of past December days reached Kp 8.

How dark is Idaho Falls in December?

Idaho Falls averages 13.8 hours of civil night a night in December 2026, from 13 h 39 min on the 1st to 13 h 48 min on the last night.

How cloudy is Idaho Falls in December?

NASA POWER's 2001 to 2020 climatology gives Idaho Falls's 1 degree cell 75% mean cloud in December, against 56% for the whole year. It is an all-hours average, not a forecast.

What is the best night in December 2026 for aurora in Idaho Falls?

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

Is December or January better in Idaho Falls?

By civil night times the clear share, December scores 3.5 hours at Idaho Falls and January 3.6. January comes out ahead.

Idaho Falls · December 2026

Northern lights in Idaho Falls in December 2026

Answer

December gives Idaho Falls 13.9 hours of civil night on the 15th, the darkest month of its year, under 75% mean cloud. 0% of December days since 1996 reached Kp 8, enough for the oval edge to reach Idaho Falls.

13.8 h

civil night, average night

SunCalc for 43.47, -112.03; NASA POWER; GFZ Kp

December against the rest of the year

3.6

3.3

3.5

3.6

3.5

4.0

5.2

5.7

6.4

5.7

4.9

3.5

December cloud at Idaho Falls averages 75% in NASA POWER's 2001 to 2020 record, 19 points cloudier than its yearly mean. July is Idaho Falls's clearest month at 33%. By civil night times clear sky, December scores 3.5 hours at Idaho Falls, 11th of 12. Lethbridge, 696 km away, averages 69%, clearer by 6 points.

Civil night at Idaho Falls starts December at 13 h 39 min and reaches 13 h 48 min by December 31 as the nights lengthen by 0.1 hours. SWPC's 10 PM to 2 AM window is fully dark on every night. True astronomical darkness, the sun 18 degrees down, lasts 11.5 hours on the 15th.

December night by night

December opens toward a new moon on Dec 8, with full moon on Dec 23, in America/Boise dates. Idaho Falls gets 230 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: Dec 2 (4 h), Dec 3 (4 h), Dec 4 (4 h).

1
39% lit
7.8 h
2
29% lit
9.0 h
3
20% lit
10.1 h
4
13% lit
11.2 h
5
7% lit
12.3 h
6
3% lit
13.4 h
7
1% lit
13.8 h
8
0% lit
13.8 h
New
9
2% lit
13.8 h
10
5% lit
13.2 h
11
9% lit
12.2 h
12
15% lit
11.1 h
13
23% lit
10.1 h
14
31% lit
9.0 h
15
41% lit
8.0 h
16
51% lit
6.9 h
17
61% lit
5.8 h
18
71% lit
4.6 h
19
81% lit
3.3 h
20
89% lit
2.0 h
21
95% lit
0.7 h
22
99% lit
0.0 h
23
100% lit
0.0 h
Full
24
98% lit
0.3 h
25
93% lit
1.6 h
26
85% lit
3.0 h
27
76% lit
4.3 h
28
66% lit
5.5 h
29
55% lit
6.7 h
30
45% lit
7.8 h
31
35% lit
8.9 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 Decembers

Idaho Falls needs Kp 8 for the average oval edge to sit overhead. 1 of the 930 December 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 5%. Idaho Falls sits at 50.3 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.

December across United States

Idaho Falls ranks 9th in United States for civil night on December 15, behind Fairbanks at 17.2 hours. Coming from November (13.2 hours at Idaho Falls), December adds darkness, and January brings shorter nights (13.5 hours on the 15th). The December solstice falls on December 21, 13:49 Idaho Falls time.

Civil night on December 15 and December cloud, month-page towns in United States
Town	Civil night	Cloud
Fairbanks	17.2 h	59%
Anchorage	16.3 h	72%
Eagle River	16.3 h	72%
Juneau	15.7 h	80%
Seattle	14.3 h	79%
Duluth	14.2 h	71%
Fargo	14.2 h	68%
Minneapolis	14.0 h	69%
Idaho Falls	13.9 h	75%
Portland, Maine	13.9 h	66%
Buffalo	13.8 h	85%

Darkness and moon, every night

Idaho Falls, December 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
Tue Dec 1	13 h 39 min	11 h 19 min	7 h 49 min	3 h 17 min	39%
Wed Dec 2	13 h 41 min	11 h 21 min	8 h 58 min	4 h	29%
Thu Dec 3	13 h 42 min	11 h 22 min	10 h 6 min	4 h	20%
Fri Dec 4	13 h 43 min	11 h 22 min	11 h 14 min	4 h	13%
Sat Dec 5	13 h 44 min	11 h 23 min	12 h 21 min	4 h	7%
Sun Dec 6	13 h 45 min	11 h 24 min	13 h 27 min	4 h	3%
Mon Dec 7	13 h 46 min	11 h 25 min	13 h 46 min	4 h	1%
Tue Dec 8	13 h 47 min	11 h 26 min	13 h 47 min	4 h	0%
Wed Dec 9	13 h 47 min	11 h 26 min	13 h 47 min	4 h	2%
Thu Dec 10	13 h 48 min	11 h 27 min	13 h 13 min	4 h	5%
Fri Dec 11	13 h 49 min	11 h 28 min	12 h 12 min	4 h	9%
Sat Dec 12	13 h 50 min	11 h 28 min	11 h 8 min	4 h	15%
Sun Dec 13	13 h 50 min	11 h 29 min	10 h 5 min	4 h	23%
Mon Dec 14	13 h 51 min	11 h 29 min	9 h 1 min	3 h 42 min	31%
Tue Dec 15	13 h 51 min	11 h 29 min	7 h 57 min	2 h 38 min	41%
Wed Dec 16	13 h 51 min	11 h 30 min	6 h 52 min	1 h 32 min	51%
Thu Dec 17	13 h 52 min	11 h 30 min	5 h 45 min	24 min	61%
Fri Dec 18	13 h 52 min	11 h 30 min	4 h 34 min	0 min	71%
Sat Dec 19	13 h 52 min	11 h 30 min	3 h 19 min	0 min	81%
Sun Dec 20	13 h 52 min	11 h 30 min	1 h 59 min	0 min	89%
Mon Dec 21	13 h 52 min	11 h 30 min	41 min	0 min	95%
Tue Dec 22	13 h 52 min	11 h 30 min	0 min	0 min	99%
Wed Dec 23	13 h 52 min	11 h 30 min	0 min	0 min	100%
Thu Dec 24	13 h 52 min	11 h 30 min	15 min	0 min	98%
Fri Dec 25	13 h 51 min	11 h 30 min	1 h 38 min	0 min	93%
Sat Dec 26	13 h 51 min	11 h 29 min	3 h	0 min	85%
Sun Dec 27	13 h 51 min	11 h 29 min	4 h 17 min	0 min	76%
Mon Dec 28	13 h 50 min	11 h 29 min	5 h 30 min	1 h 5 min	66%
Tue Dec 29	13 h 50 min	11 h 28 min	6 h 40 min	2 h 16 min	55%
Wed Dec 30	13 h 49 min	11 h 28 min	7 h 49 min	3 h 25 min	45%
Thu Dec 31	13 h 48 min	11 h 27 min	8 h 56 min	4 h	35%

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

Questions

Can you see the northern lights in Idaho Falls in December?: On dark, clear nights with enough activity. 31 of 31 nights at Idaho Falls have civil darkness, and 0% of past December days reached Kp 8.
How dark is Idaho Falls in December?: Idaho Falls averages 13.8 hours of civil night a night in December 2026, from 13 h 39 min on the 1st to 13 h 48 min on the last night.
How cloudy is Idaho Falls in December?: NASA POWER's 2001 to 2020 climatology gives Idaho Falls's 1 degree cell 75% mean cloud in December, against 56% for the whole year. It is an all-hours average, not a forecast.
What is the best night in December 2026 for aurora in Idaho Falls?: By darkness and moon alone, Dec 2, with 4 h of moon-free darkness inside 10 PM to 2 AM at Idaho Falls. Activity on that date will only be known hours ahead.
Is December or January better in Idaho Falls?: By civil night times the clear share, December scores 3.5 hours at Idaho Falls and January 3.6. January 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.