Is Grande Prairie or Fort St. John better for the northern lights?

Fort St. John sits closer to the oval, at 61.7 degrees geomagnetic against 60.9. Darkness, cloud and your dates decide the rest; the tables on this page show both towns month by month.

Which has longer nights in December, Grande Prairie or Fort St. John?

Fort St. John, with 15.4 hours of civil night on December 15 against 15.2 in Grande Prairie.

What Kp do Grande Prairie and Fort St. John need?

By SWPC's rule of 66 degrees at Kp 0 and 2 degrees per step, Grande Prairie needs about Kp 3 and Fort St. John Kp 3 for the average oval edge to sit overhead.

When is it too light for aurora in Grande Prairie and Fort St. John?

Grande Prairie: never, every night has civil darkness. Fort St. John: never, every night has civil darkness.

Which is clearer, Grande Prairie or Fort St. John?

Grande Prairie, with 67% mean cloud in the months with 4 hours or more of civil night against 67% in Fort St. John (NASA POWER, 2001 to 2020).

Comparison

Grande Prairie vs Fort St. John for the northern lights

Answer

Fort St. John sits 0.8 degrees higher on the IGRF-14 dipole, 61.7 against 60.9. By SWPC's oval-edge rule Fort St. John needs about Kp 3 for the average edge to sit overhead and Grande Prairie Kp 3. On the map Fort St. John is also closer to the pole, by 1.1 degrees.

60.9° / 61.7°

dipole latitude

Side by side

Computed figures for both towns
Figure	Grande Prairie	Fort St. John
Dipole latitude	60.9°	61.7°
Kp for the oval edge overhead	Kp 3	Kp 3
Civil night, December 15	15.2 h	15.4 h
Dark-season days	365	352
Nights with no civil darkness	0	0
Dark-month cloud, NASA POWER	67%	67%
Solar midnight, December 15	01:50	00:59

Grande Prairie sits at 60.9 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. 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.

Civil night month by month

On December 15 Grande Prairie has 15.2 hours of civil night and Fort St. John 15.4. Across the 15th of each month, Grande Prairie is darker in 6 months and Fort St. John in 3. The widest gap comes in June, when Grande Prairie has 0.4 more hours.

Hours of civil night on the 15th of each month, 2026
Month	Grande Prairie	Fort St. John	Difference
January	14.6 h	14.8 h	-0.2 h
February	12.9 h	12.9 h	+0.0 h
March	10.8 h	10.8 h	+0.0 h
April	8.4 h	8.2 h	+0.2 h
May	6.0 h	5.7 h	+0.3 h
June	4.4 h	4.0 h	+0.4 h
July	5.3 h	4.9 h	+0.4 h
August	7.5 h	7.3 h	+0.2 h
September	10.0 h	9.9 h	+0.1 h
October	12.2 h	12.2 h	+0.0 h
November	14.2 h	14.3 h	-0.1 h
December	15.2 h	15.4 h	-0.2 h

Difference: Grande Prairie minus Fort St. John. Each figure links to that town's month page.

Season and midnight sun

Grande Prairie has some civil darkness every night of 2026, and clears Glow's 4-hour dark-season bar every evening. Fort St. John has some civil darkness every night of 2026, and its dark season, 4 or more evening hours of civil night, lasts 352 days.

Distance, cloud and time zones

The two towns are 176 km apart by great circle. In the dark months both average about 67% cloud in NASA POWER's 2001 to 2020 record. Grande Prairie's best month by civil night times clear sky is December. Fort St. John's best month by civil night times clear sky is December. Time zones: America/Edmonton and America/Dawson_Creek.

For tonight, open the live pages for Grande Prairie and Fort St. John, which carry the live OVATION cell.

Questions

Is Grande Prairie or Fort St. John better for the northern lights?: Fort St. John sits closer to the oval, at 61.7 degrees geomagnetic against 60.9. Darkness, cloud and your dates decide the rest; the tables on this page show both towns month by month.
Which has longer nights in December, Grande Prairie or Fort St. John?: Fort St. John, with 15.4 hours of civil night on December 15 against 15.2 in Grande Prairie.
What Kp do Grande Prairie and Fort St. John need?: By SWPC's rule of 66 degrees at Kp 0 and 2 degrees per step, Grande Prairie needs about Kp 3 and Fort St. John Kp 3 for the average oval edge to sit overhead.
When is it too light for aurora in Grande Prairie and Fort St. John?: Grande Prairie: never, every night has civil darkness. Fort St. John: never, every night has civil darkness.
Which is clearer, Grande Prairie or Fort St. John?: Grande Prairie, with 67% mean cloud in the months with 4 hours or more of civil night against 67% in Fort St. John (NASA POWER, 2001 to 2020).

Sources and verification

IGRF-14 coefficients, NOAA NCEIhttps://www.ngdc.noaa.gov/IAGA/vmod/coeffs/igrf14coeffs.txt
SunCalchttps://github.com/mourner/suncalc
GeoNameshttps://www.geonames.org/export/
NASA POWER climatologyhttps://power.larc.nasa.gov/docs/services/api/temporal/climatology/
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.