Quebec, Canada
Northern lights in Longueuil
Answer
Tonight
Waiting on darkness
It is not civil-dark yet. The next dusk is listed below.
Observed 11:49 UTC, forecast 13:20 UTC, 91 min lead
Clock times in America/Toronto
Storm level needed
Longueuil sits at 45.52N 73.47W in Quebec, Canada. The IGRF-14 centered dipole puts Longueuil at 54.7 degrees geomagnetic latitude, 9.2 degrees closer to the magnetic pole than its map latitude suggests. Longueuil sits at 54.7 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 6.
"aurora has been seen as low as Illinois and Oregon (typically 50° geomagnetic lat.)"
The nearest other Glow towns are Montréal (9 km), Laval (18 km), Repentigny (25 km). Montréal sits 0.0 degrees lower on the dipole and needs the same Kp.
Approximate: SWPC calls its Kp to latitude rule an average, and a centered dipole can differ by a degree from fuller field models. How the storm level is matched
The year in darkness
Every night of 2026 at Longueuil has some civil darkness; the shortest month sample still has 6.9 hours. Every evening of the year at Longueuil clears Glow's dark-season bar of 4 hours of civil night between 18:00 and 06:00. Longueuil's longest night of the year, Dec 19, has 14 h 4 min of civil night.
Solar midnight at Longueuil, when the sun is lowest, falls at 23:49 on local clocks on December 15 and 00:54 on June 15. That is 11 min before midnight in December and 54 min after midnight in June, the gap set by daylight saving and the equation of time. So at Longueuil the darkest hour sits near the middle of SWPC's 10 PM to 2 AM window in winter.
Month by month
| Month | Night | Civil | Cloud | Clear dark | |
|---|---|---|---|---|---|
| Jan | 13.7 h | 11.3 h | 69% | 4.2 h | |
| Feb | 12.4 h | 10.2 h | 68% | 4.0 h | |
| Mar | 11.0 h | 8.7 h | 65% | 3.8 h | |
| Apr | 9.3 h | 6.7 h | 67% | 3.1 h | |
| May | 7.8 h | 4.5 h | 66% | 2.7 h | |
| Jun | 6.9 h | 2.8 h | 62% | 2.6 h | |
| Jul | 7.3 h | 3.7 h | 58% | 3.1 h | |
| Aug | 8.7 h | 5.9 h | 57% | 3.7 h | |
| Sep | 10.4 h | 8.0 h | 54% | 4.8 hbest | |
| Oct | 12.0 h | 9.7 h | 68% | 3.8 h | |
| Nov | 13.3 h | 11.0 h | 72% | 3.8 h | |
| Dec | 14.0 h | 11.6 h | 76% | 3.4 h |
By the 15th-of-the-month sample, December is the darkest month at Longueuil with 14.0 hours of civil night and June the lightest at 6.9. Across the year Longueuil gets 3,861 hours of civil night. Astronomical night at Longueuil, the sun 18 degrees or more below the horizon, lasts 11.6 hours on December 15.
NASA POWER's 2001 to 2020 all-hours climatology puts mean cloud amount for the 1 degree cell around Longueuil at 65% across the year, from 54% in September to 76% in December. In the months with at least 4 hours of civil night Longueuil averages 65%, against a median of 67% for Glow towns in Canada.
Multiplying civil night by the clear share of the sky gives September the best score, 4.8 hours, ahead of January at 4.2. Longueuil's equinox months score 3.8 in March and 4.8 in September, the weeks SWPC links with larger storms.
Kp history
From 1996 to 2025, the GFZ Potsdam record shows a 3-hour Kp of 6 or more, the level that puts the average oval edge over Longueuil, on 3% of days. At Longueuil's level the share runs from 1% in December to 5% in October, while storm days with Kp 5 or more made up 10%.
Share of UTC days in each calendar month whose highest 3-hour Kp reached Kp 6. Kp history by year
Moon, next 30 nights
Over the 30 nights from Oct 1, the new moon falls on Oct 10 and the full moon on Oct 26, in America/Toronto dates. 15 of the 30 nights at Longueuil have at least 2 moon-free dark hours inside 10 PM to 2 AM, and Oct 5 has the most at 4 h. Tonight Longueuil has 11 h 15 min of civil night, 2 h 8 min of it with the moon down.
- 1
66% lit
2.1 h
- 2
55% lit
3.2 h
- 3
43% lit
4.5 h
- 4
32% lit
5.9 h
- 5
22% lit
7.2 h
- 6
14% lit
8.5 h
- 7
7% lit
9.8 h
- 8
3% lit
11.0 h
- 9
0% lit
11.7 h
- 10
0% lit
11.7 h
- 11
3% lit
11.8 h
- 12
7% lit
11.8 h
- 13
12% lit
11.4 h
- 14
19% lit
10.8 h
- 15
27% lit
10.1 h
- 16
36% lit
9.2 h
- 17
45% lit
8.2 h
- 18
55% lit
7.1 h
- 19
64% lit
6.0 h
- 20
73% lit
4.8 h
- 21
82% lit
3.7 h
- 22
89% lit
2.6 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
- 27
94% lit
0.0 h
- 28
88% lit
0.8 h
- 29
79% lit
1.9 h
- 30
69% lit
3.1 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.
Within Canada
Among the 32 Glow towns in Quebec, Longueuil ranks 27th by dipole latitude against a regional median of 55.3 degrees; Sept-Îles sits highest at 59.3. Among the 131 Glow towns in Canada, Longueuil ranks 85th by dipole latitude against a national median of 55.3 degrees; Yellowknife sits highest at 68.5. On December 15 Longueuil gets 14.0 hours of civil night, 94th longest of 131 in Canada, where the median is 14.2.
Questions
- Can you see the northern lights in Longueuil?
- Longueuil sits at 54.7 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 6. Clear, dark sky over Longueuil still decides it.
- When is it dark enough in Longueuil?
- Every night at Longueuil has civil darkness. Tonight has 11 h 15 min, and December 15 has 14.0 hours.
- What is the best month for aurora in Longueuil?
- September, by civil night at Longueuil times the clear share of the sky from NASA POWER's 2001 to 2020 average.
- How cloudy is Longueuil in the dark months?
- About 65% mean cloud amount over Longueuil in the months with at least 4 hours of civil night, from NASA POWER's 2001 to 2020 all-hours climatology.
- How often is activity high enough for Longueuil?
- A 3-hour Kp of 6 or more, the level that puts the average oval edge overhead, occurred on 3% of days from 1996 to 2025 in the GFZ Potsdam record.
- Why does this page point to Montréal?
- Longueuil sits within 15 km of Montréal with the same rounded dipole latitude, Kp and dark season, so Glow treats Montréal as the main page for both.
Nearby and related
Nearest Glow towns
Longueuil by month
Region and comparisons