Can you see the northern lights in Fort St. John in August?

On dark, clear nights with enough activity. 31 of 31 nights at Fort St. John have civil darkness, and 48% of past August days reached Kp 3.

How dark is Fort St. John in August?

Fort St. John averages 7.4 hours of civil night a night in August 2027, from 6 h 9 min on the 1st to 8 h 39 min on the last night.

How cloudy is Fort St. John in August?

NASA POWER's 2001 to 2020 climatology gives Fort St. John's 1 degree cell 63% mean cloud in August, against 67% for the whole year. It is an all-hours average, not a forecast.

What is the best night in August 2027 for aurora in Fort St. John?

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

Is August or September better in Fort St. John?

By civil night times the clear share, August scores 2.7 hours at Fort St. John and September 3.5. September comes out ahead.

Fort St. John · August 2027

Northern lights in Fort St. John in August 2027

Answer

August gives Fort St. John 7.3 hours of civil night on the 15th, the 9th darkest of its 12 months, under 63% mean cloud. 48% of August days since 1996 reached Kp 3, enough for the oval edge to reach Fort St. John.

7.4 h

civil night, average night

SunCalc for 56.25, -120.85; NASA POWER; GFZ Kp

August against the rest of the year

4.4

4.3

3.5

2.7

1.9

1.3

1.8

2.7

3.5

3.9

4.8

August cloud at Fort St. John averages 63% in NASA POWER's 2001 to 2020 record, 4 points clearer than its yearly mean. July is Fort St. John's clearest month at 63%. By civil night times clear sky, August scores 2.7 hours at Fort St. John, 9th of 12. Grande Prairie, 176 km away, averages 61%, clearer by 2 points.

Civil night at Fort St. John starts August at 6 h 9 min and reaches 8 h 39 min by August 31 as the nights lengthen by 2.5 hours. The 10 PM to 2 AM window is fully dark on 29 of 31 nights. True astronomical darkness, the sun 18 degrees down, lasts 2.4 hours on the 15th.

August night by night

August opens toward a new moon on Aug 2 and Aug 31, with full moon on Aug 17, in America/Dawson_Creek dates. Fort St. John gets 115 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: Aug 4 (4 h), Aug 5 (4 h), Aug 6 (4 h).

1
0% lit
6.2 h
2
1% lit
6.2 h
New
3
5% lit
6.3 h
4
12% lit
6.4 h
5
20% lit
6.5 h
6
30% lit
6.5 h
7
41% lit
6.5 h
8
51% lit
6.3 h
9
61% lit
6.0 h
10
71% lit
5.5 h
11
79% lit
4.8 h
12
86% lit
3.8 h
13
92% lit
2.6 h
14
96% lit
1.3 h
15
99% lit
0.0 h
16
100% lit
0.0 h
17
99% lit
0.0 h
Full
18
96% lit
0.0 h
19
92% lit
0.0 h
20
86% lit
0.0 h
21
78% lit
0.0 h
22
69% lit
0.0 h
23
59% lit
0.3 h
24
48% lit
0.8 h
25
37% lit
1.6 h
26
26% lit
2.7 h
27
17% lit
4.2 h
28
9% lit
5.9 h
29
3% lit
7.7 h
30
0% lit
8.6 h
31
1% lit
8.7 h
New

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 Augusts

Fort St. John needs Kp 3 for the average oval edge to sit overhead. 444 of the 930 August days from 1996 to 2025 (48%) reached it in the GFZ Potsdam record, 7th of 12 months; storm days with Kp 5 or more made up 11%. Fort St. John sits at 61.7 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.

August across Canada

Fort St. John ranks 20th in Canada for civil night on August 15, behind Trois-Rivières at 8.7 hours. Coming from July (4.9 hours at Fort St. John), August adds darkness, and the nights keep growing into September (9.9 hours on the 15th).

Civil night on August 15 and August cloud, month-page towns in Canada
Town	Civil night	Cloud
Trois-Rivières	8.7 h	59%
Sydney	8.7 h	65%
Québec	8.6 h	60%
Greater Sudbury	8.6 h	56%
St. John's	8.5 h	72%
Saguenay	8.4 h	68%
Thunder Bay	8.4 h	64%
Winnipeg	8.3 h	52%
Kelowna	8.3 h	45%
Lethbridge	8.3 h	51%
Regina	8.2 h	53%
Kamloops	8.2 h	50%
Fort St. John	7.3 h	63%

Darkness and moon, every night

Fort St. John, August 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
Sun Aug 1	6 h 9 min	0 min	6 h 9 min	3 h 54 min	0%
Mon Aug 2	6 h 14 min	0 min	6 h 14 min	3 h 57 min	1%
Tue Aug 3	6 h 19 min	0 min	6 h 19 min	3 h 59 min	5%
Wed Aug 4	6 h 23 min	0 min	6 h 23 min	4 h	12%
Thu Aug 5	6 h 28 min	0 min	6 h 28 min	4 h	20%
Fri Aug 6	6 h 33 min	0 min	6 h 33 min	4 h	30%
Sat Aug 7	6 h 38 min	0 min	6 h 31 min	4 h	41%
Sun Aug 8	6 h 43 min	0 min	6 h 20 min	3 h 48 min	51%
Mon Aug 9	6 h 48 min	0 min	6 h 1 min	3 h 28 min	61%
Tue Aug 10	6 h 53 min	0 min	5 h 32 min	2 h 56 min	71%
Wed Aug 11	6 h 58 min	59 min	4 h 47 min	2 h 9 min	79%
Thu Aug 12	7 h 4 min	1 h 26 min	3 h 47 min	1 h 6 min	86%
Fri Aug 13	7 h 9 min	1 h 47 min	2 h 35 min	0 min	92%
Sat Aug 14	7 h 14 min	2 h 4 min	1 h 19 min	0 min	96%
Sun Aug 15	7 h 19 min	2 h 19 min	2 min	0 min	99%
Mon Aug 16	7 h 24 min	2 h 33 min	0 min	0 min	100%
Tue Aug 17	7 h 29 min	2 h 46 min	0 min	0 min	99%
Wed Aug 18	7 h 34 min	2 h 58 min	0 min	0 min	96%
Thu Aug 19	7 h 39 min	3 h 10 min	0 min	0 min	92%
Fri Aug 20	7 h 44 min	3 h 21 min	0 min	0 min	86%
Sat Aug 21	7 h 49 min	3 h 31 min	0 min	0 min	78%
Sun Aug 22	7 h 54 min	3 h 41 min	1 min	0 min	69%
Mon Aug 23	7 h 59 min	3 h 51 min	20 min	0 min	59%
Tue Aug 24	8 h 4 min	4 h	49 min	0 min	48%
Wed Aug 25	8 h 9 min	4 h 9 min	1 h 34 min	36 min	37%
Thu Aug 26	8 h 14 min	4 h 18 min	2 h 43 min	1 h 41 min	26%
Fri Aug 27	8 h 19 min	4 h 26 min	4 h 13 min	3 h 9 min	17%
Sat Aug 28	8 h 24 min	4 h 35 min	5 h 55 min	4 h	9%
Sun Aug 29	8 h 29 min	4 h 43 min	7 h 39 min	4 h	3%
Mon Aug 30	8 h 34 min	4 h 51 min	8 h 34 min	4 h	0%
Tue Aug 31	8 h 39 min	4 h 58 min	8 h 39 min	4 h	1%

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

Questions

Can you see the northern lights in Fort St. John in August?: On dark, clear nights with enough activity. 31 of 31 nights at Fort St. John have civil darkness, and 48% of past August days reached Kp 3.
How dark is Fort St. John in August?: Fort St. John averages 7.4 hours of civil night a night in August 2027, from 6 h 9 min on the 1st to 8 h 39 min on the last night.
How cloudy is Fort St. John in August?: NASA POWER's 2001 to 2020 climatology gives Fort St. John's 1 degree cell 63% mean cloud in August, against 67% for the whole year. It is an all-hours average, not a forecast.
What is the best night in August 2027 for aurora in Fort St. John?: By darkness and moon alone, Aug 4, with 4 h of moon-free darkness inside 10 PM to 2 AM at Fort St. John. Activity on that date will only be known hours ahead.
Is August or September better in Fort St. John?: By civil night times the clear share, August scores 2.7 hours at Fort St. John and September 3.5. September 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.