Can you see the northern lights in Yellowknife in May?

On dark, clear nights with enough activity. 24 of 31 nights at Yellowknife have civil darkness, and 10% of past May days reached Kp 5.

How dark is Yellowknife in May?

Yellowknife averages 2.6 hours of civil night a night in May 2027, from 5 h 10 min on the 1st to 0 min on the last night.

How cloudy is Yellowknife in May?

NASA POWER's 2001 to 2020 climatology gives Yellowknife's 1 degree cell 66% mean cloud in May, against 63% for the whole year. It is an all-hours average, not a forecast.

What is the best night in May 2027 for aurora in Yellowknife?

By darkness and moon alone, May 1, with 3 h 1 min of moon-free darkness inside 10 PM to 2 AM at Yellowknife. Activity on that date will only be known hours ahead.

Is May or June better in Yellowknife?

By civil night times the clear share, May scores 1.0 hours at Yellowknife and June 0.0. May comes out ahead.

Yellowknife · May 2027

Northern lights in Yellowknife in May 2027

Answer

May gives Yellowknife 3.0 hours of civil night on the 15th, the 10th darkest of its 12 months, under 66% mean cloud. 10% of May days since 1996 reached storm level, Kp 5.

2.6 h

civil night, average night

SunCalc for 62.45, -114.37; NASA POWER; GFZ Kp

May against the rest of the year

7.0

6.5

5.4

3.0

1.0

0.0

2.1

3.2

2.4

3.8

7.0

May cloud at Yellowknife averages 66% in NASA POWER's 2001 to 2020 record, 3 points cloudier than its yearly mean. March is Yellowknife's clearest month at 49%. By civil night times clear sky, May scores 1.0 hours at Yellowknife, 10th of 12. Fort McMurray, 659 km away, averages 63%, clearer by 3 points.

Civil night at Yellowknife starts May at 5 h 10 min and reaches 0 min by May 31, 5.2 hours shorter. 7 Yellowknife nights this month have no civil darkness at all. No night keeps the 10 PM to 2 AM window fully dark at Yellowknife. The sun never reaches 18 degrees down, so Yellowknife gets no astronomical night in May.

May night by night

May opens toward a new moon on May 6, with full moon on May 20, in America/Edmonton dates. Yellowknife gets 36 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: May 1 (3 h 1 min), May 2 (2 h 57 min), May 3 (2 h 53 min).

1
19% lit
5.2 h
2
12% lit
5.0 h
3
6% lit
4.9 h
4
2% lit
4.8 h
5
0% lit
4.6 h
6
1% lit
3.8 h
New
7
4% lit
1.8 h
8
10% lit
0.4 h
9
19% lit
0.0 h
10
28% lit
0.0 h
11
39% lit
0.0 h
12
51% lit
0.0 h
13
62% lit
0.0 h
14
72% lit
0.0 h
15
81% lit
0.0 h
16
89% lit
0.0 h
17
95% lit
0.0 h
18
98% lit
0.0 h
19
100% lit
0.0 h
20
99% lit
0.7 h
Full
21
97% lit
1.8 h
22
92% lit
1.5 h
23
87% lit
1.2 h
24
80% lit
0.8 h
25
72% lit
no night
26
63% lit
no night
27
53% lit
no night
28
44% lit
no night
29
34% lit
no night
30
25% lit
no night
31
16% lit
no night

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 Mays

Quiet activity already puts the oval edge over Yellowknife, so storm days matter more: 97 of the 930 May days from 1996 to 2025 (10%) reached Kp 5, 6th of 12 months. Yellowknife sits at 68.5 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.

May across Canada

Yellowknife ranks 23rd in Canada for civil night on May 15, behind Greater Sudbury at 7.7 hours. Coming from April (7.2 hours at Yellowknife), May loses darkness, and June brings shorter nights (0.0 hours on the 15th).

Civil night on May 15 and May cloud, month-page towns in Canada
Town	Civil night	Cloud
Greater Sudbury	7.7 h	64%
Trois-Rivières	7.7 h	66%
Sydney	7.7 h	72%
Québec	7.6 h	69%
St. John's	7.5 h	77%
Saguenay	7.4 h	71%
Thunder Bay	7.4 h	73%
Lethbridge	7.2 h	65%
Winnipeg	7.1 h	60%
Kelowna	7.1 h	68%
Regina	7.0 h	62%
Kamloops	7.0 h	70%
Yellowknife	3.0 h	66%

Darkness and moon, every night

Yellowknife, May 2027: each night from local noon to the next noon
Night	Civil	Moon-free dark	Moon-free, 10 PM to 2 AM	Moon lit
Sat May 1	5 h 10 min	5 h 10 min	3 h 1 min	19%
Sun May 2	5 h 2 min	5 h 2 min	2 h 57 min	12%
Mon May 3	4 h 54 min	4 h 54 min	2 h 53 min	6%
Tue May 4	4 h 46 min	4 h 46 min	2 h 49 min	2%
Wed May 5	4 h 37 min	4 h 37 min	2 h 45 min	0%
Thu May 6	4 h 29 min	3 h 46 min	1 h 58 min	1%
Fri May 7	4 h 20 min	1 h 45 min	2 min	4%
Sat May 8	4 h 11 min	24 min	0 min	10%
Sun May 9	4 h 2 min	0 min	0 min	19%
Mon May 10	3 h 53 min	0 min	0 min	28%
Tue May 11	3 h 43 min	0 min	0 min	39%
Wed May 12	3 h 34 min	0 min	0 min	51%
Thu May 13	3 h 24 min	0 min	0 min	62%
Fri May 14	3 h 14 min	0 min	0 min	72%
Sat May 15	3 h 3 min	0 min	0 min	81%
Sun May 16	2 h 52 min	0 min	0 min	89%
Mon May 17	2 h 41 min	0 min	0 min	95%
Tue May 18	2 h 29 min	0 min	0 min	98%
Wed May 19	2 h 17 min	0 min	0 min	100%
Thu May 20	2 h 3 min	44 min	44 min	99%
Fri May 21	1 h 49 min	1 h 49 min	1 h 20 min	97%
Sat May 22	1 h 32 min	1 h 32 min	1 h 12 min	92%
Sun May 23	1 h 13 min	1 h 13 min	1 h 2 min	87%
Mon May 24	47 min	47 min	47 min	80%
Tue May 25	0 min	0 min	0 min	72%
Wed May 26	0 min	0 min	0 min	63%
Thu May 27	0 min	0 min	0 min	53%
Fri May 28	0 min	0 min	0 min	44%
Sat May 29	0 min	0 min	0 min	34%
Sun May 30	0 min	0 min	0 min	25%
Mon May 31	0 min	0 min	0 min	16%

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

Questions

Can you see the northern lights in Yellowknife in May?: On dark, clear nights with enough activity. 24 of 31 nights at Yellowknife have civil darkness, and 10% of past May days reached Kp 5.
How dark is Yellowknife in May?: Yellowknife averages 2.6 hours of civil night a night in May 2027, from 5 h 10 min on the 1st to 0 min on the last night.
How cloudy is Yellowknife in May?: NASA POWER's 2001 to 2020 climatology gives Yellowknife's 1 degree cell 66% mean cloud in May, against 63% for the whole year. It is an all-hours average, not a forecast.
What is the best night in May 2027 for aurora in Yellowknife?: By darkness and moon alone, May 1, with 3 h 1 min of moon-free darkness inside 10 PM to 2 AM at Yellowknife. Activity on that date will only be known hours ahead.
Is May or June better in Yellowknife?: By civil night times the clear share, May scores 1.0 hours at Yellowknife and June 0.0. May 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.