Stockholm, Sweden
Northern lights in Trångsund
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 Europe/Stockholm
Storm level needed
Trångsund sits at 59.23N 18.13E in Stockholm, Sweden. The IGRF-14 centered dipole puts Trångsund at 57.9 degrees geomagnetic latitude, 1.4 degrees farther from the magnetic pole than its map latitude suggests. Trångsund sits at 57.9 degrees geomagnetic. By SWPC's rule the average oval edge is overhead at Kp 5, and aurora is usually visible on the northern horizon at G1 (Kp 5) or less.
"aurora is commonly visible at high latitudes (northern Michigan and Maine)"
The nearest other Glow towns are Haninge (7 km), Stockholm (11 km), Gustavsberg (18 km). Haninge sits 0.1 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 Trångsund has some civil darkness; the shortest month sample still has 2.0 hours. Glow's dark season, at least 4 hours of civil night between 18:00 and 06:00, runs from July 20 to May 22 across New Year, 307 days in 2026. Trångsund's longest night of the year, Dec 19, has 15 h 54 min of civil night.
Solar midnight at Trångsund, when the sun is lowest, falls at 23:43 on local clocks on December 15 and 00:48 on June 15. That is 17 min before midnight in December and 48 min after midnight in June, the gap set by daylight saving and the equation of time. So at Trångsund 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 | 15.2 h | 11.8 h | 89% | 1.7 h | |
| Feb | 13.1 h | 9.9 h | 86% | 1.8 h | |
| Mar | 10.7 h | 7.4 h | 78% | 2.4 h | |
| Apr | 7.8 h | 3.0 h | 69% | 2.4 h | |
| May | 4.8 h | 0.0 h | 62% | 1.8 h | |
| Jun | 2.0 h | 0.0 h | 62% | 0.8 h | |
| Jul | 3.5 h | 0.0 h | 63% | 1.3 h | |
| Aug | 6.7 h | 0.0 h | 68% | 2.1 h | |
| Sep | 9.7 h | 6.1 h | 72% | 2.7 hbest | |
| Oct | 12.3 h | 9.1 h | 81% | 2.3 h | |
| Nov | 14.6 h | 11.3 h | 87% | 1.9 h | |
| Dec | 15.8 h | 12.4 h | 88% | 1.9 h |
By the 15th-of-the-month sample, December is the darkest month at Trångsund with 15.9 hours of civil night and June the lightest at 2.0. Across the year Trångsund gets 3,532 hours of civil night. Astronomical night at Trångsund, the sun 18 degrees or more below the horizon, lasts 12.4 hours on December 15.
NASA POWER's 2001 to 2020 all-hours climatology puts mean cloud amount for the 1 degree cell around Trångsund at 75% across the year, from 62% in May to 89% in January. In the months with at least 4 hours of civil night Trångsund averages 78%, against a median of 75% for Glow towns in Sweden.
Multiplying civil night by the clear share of the sky gives September the best score, 2.7 hours, ahead of April at 2.4. Trångsund's equinox months score 2.4 in March and 2.7 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 5 or more, the level that puts the average oval edge over Trångsund, on 10% of days. At Trångsund's level the share runs from 5% in December to 14% in September, 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 5. Kp history by year
Moon, next 30 nights
Over the 30 nights from Oct 2, the new moon falls on Oct 10 and the full moon on Oct 26, in Europe/Stockholm dates. 15 of the 30 nights at Trångsund have at least 2 moon-free dark hours inside 10 PM to 2 AM, and Oct 6 has the most at 4 h. Tonight Trångsund has 11 h 10 min of civil night, 52 min of it with the moon down.
- 2
57% lit
0.9 h
- 3
46% lit
2.4 h
- 4
35% lit
4.1 h
- 5
25% lit
5.9 h
- 6
16% lit
7.6 h
- 7
8% lit
9.3 h
- 8
3% lit
10.8 h
- 9
1% lit
11.8 h
- 10
0% lit
11.8 h
- 11
2% lit
11.9 h
- 12
5% lit
12.0 h
- 13
11% lit
12.1 h
- 14
17% lit
12.2 h
- 15
25% lit
12.3 h
- 16
34% lit
11.7 h
- 17
43% lit
10.5 h
- 18
52% lit
9.1 h
- 19
62% lit
7.6 h
- 20
71% lit
6.1 h
- 21
80% lit
4.7 h
- 22
87% lit
3.3 h
- 23
94% lit
1.8 h
- 24
98% lit
0.2 h
- 25
100% lit
0.0 h
- 26
99% lit
0.0 h
- 27
95% lit
0.0 h
- 28
89% lit
0.0 h
- 29
81% lit
0.0 h
- 30
71% lit
1.3 h
- 31
60% lit
3.0 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 Sweden
Among the 9 Glow towns in Stockholm, Trångsund ranks 8th by dipole latitude against a regional median of 58.0 degrees; Märsta sits highest at 58.3. Among the 75 Glow towns in Sweden, Trångsund ranks 39th by dipole latitude against a national median of 57.9 degrees; Kiruna sits highest at 65.7. On December 15 Trångsund gets 15.9 hours of civil night, 19th longest of 75 in Sweden, where the median is 15.8.
Questions
- Can you see the northern lights in Trångsund?
- Trångsund sits at 57.9 degrees geomagnetic. By SWPC's rule the average oval edge is overhead at Kp 5, and aurora is usually visible on the northern horizon at G1 (Kp 5) or less. Clear, dark sky over Trångsund still decides it.
- When is it dark enough in Trångsund?
- Every night at Trångsund has civil darkness. Tonight has 11 h 10 min, and December 15 has 15.9 hours.
- What is the best month for aurora in Trångsund?
- September, by civil night at Trångsund times the clear share of the sky from NASA POWER's 2001 to 2020 average.
- How cloudy is Trångsund in the dark months?
- About 78% mean cloud amount over Trångsund 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 Trångsund?
- A 3-hour Kp of 5 or more, the level that puts the average oval edge overhead, occurred on 10% of days from 1996 to 2025 in the GFZ Potsdam record.
- Why does this page point to Stockholm?
- Trångsund sits within 15 km of Stockholm with the same rounded dipole latitude, Kp and dark season, so Glow treats Stockholm as the main page for both.
Nearby and related
Nearest Glow towns
Trångsund by month
Region and comparisons