Vestfold, Norway
Northern lights in Horten
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/Oslo
Storm level needed
Horten sits at 59.42N 10.48E in Vestfold, Norway. The IGRF-14 centered dipole puts Horten at 59.2 degrees geomagnetic latitude, 0.2 degrees farther from the magnetic pole than its map latitude suggests. Horten sits at 59.2 degrees geomagnetic. By SWPC's rule the average oval edge is overhead at Kp 4, 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 Moss (10 km), Tønsberg (17 km), Fredrikstad (34 km). Moss 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 Horten has some civil darkness; the shortest month sample still has 1.8 hours. Glow's dark season, at least 4 hours of civil night between 18:00 and 06:00, runs from July 21 to May 21 across New Year, 305 days in 2026. Horten's longest night of the year, Dec 19, has 15 h 56 min of civil night.
Solar midnight at Horten, when the sun is lowest, falls at 00:13 on local clocks on December 15 and 01:18 on June 15. That is 13 min after midnight in December and 1 h 18 min after midnight in June, the gap set by daylight saving and the equation of time. So at Horten 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 | 11.9 h | 83% | 2.6 h | |
| Feb | 13.1 h | 9.9 h | 82% | 2.4 h | |
| Mar | 10.7 h | 7.4 h | 74% | 2.8 h | |
| Apr | 7.8 h | 2.8 h | 70% | 2.3 h | |
| May | 4.7 h | 0.0 h | 68% | 1.5 h | |
| Jun | 1.8 h | 0.0 h | 68% | 0.6 h | |
| Jul | 3.4 h | 0.0 h | 71% | 1.0 h | |
| Aug | 6.7 h | 0.0 h | 71% | 1.9 h | |
| Sep | 9.7 h | 6.0 h | 73% | 2.6 h | |
| Oct | 12.3 h | 9.1 h | 77% | 2.8 h | |
| Nov | 14.6 h | 11.3 h | 82% | 2.6 h | |
| Dec | 15.9 h | 12.4 h | 82% | 2.9 hbest |
By the 15th-of-the-month sample, December is the darkest month at Horten with 15.9 hours of civil night and June the lightest at 1.8. Across the year Horten gets 3,521 hours of civil night. Astronomical night at Horten, 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 Horten at 75% across the year, from 68% in May to 83% in January. In the months with at least 4 hours of civil night Horten averages 76%, against a median of 77% for Glow towns in Norway.
Multiplying civil night by the clear share of the sky gives December the best score, 2.9 hours, ahead of October at 2.8. Horten's equinox months score 2.8 in March and 2.6 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 4 or more, the level that puts the average oval edge over Horten, on 24% of days. At Horten's level the share runs from 19% in December to 31% 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 4. 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/Oslo dates. 15 of the 30 nights at Horten have at least 2 moon-free dark hours inside 10 PM to 2 AM, and Oct 6 has the most at 4 h. Tonight Horten has 11 h 10 min of civil night, 50 min of it with the moon down.
- 2
57% lit
0.8 h
- 3
46% lit
2.4 h
- 4
35% lit
4.2 h
- 5
25% lit
6.0 h
- 6
16% lit
7.7 h
- 7
8% lit
9.3 h
- 8
3% lit
10.9 h
- 9
1% lit
11.8 h
- 10
0% lit
11.9 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
11.8 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
3.2 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
3.1 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 Norway
Among the 3 Glow towns in Vestfold, Horten ranks 1st by dipole latitude against a regional median of 59.1 degrees, the highest of them. Among the 33 Glow towns in Norway, Horten ranks 24th by dipole latitude against a national median of 59.7 degrees; Tromsø sits highest at 67.5. On December 15 Horten gets 15.9 hours of civil night, 20th longest of 33 in Norway, where the median is 16.0.
Questions
- Can you see the northern lights in Horten?
- Horten sits at 59.2 degrees geomagnetic. By SWPC's rule the average oval edge is overhead at Kp 4, and aurora is usually visible on the northern horizon at G1 (Kp 5) or less. Clear, dark sky over Horten still decides it.
- When is it dark enough in Horten?
- Every night at Horten has civil darkness. Tonight has 11 h 10 min, and December 15 has 15.9 hours.
- What is the best month for aurora in Horten?
- December, by civil night at Horten times the clear share of the sky from NASA POWER's 2001 to 2020 average.
- How cloudy is Horten in the dark months?
- About 76% mean cloud amount over Horten 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 Horten?
- A 3-hour Kp of 4 or more, the level that puts the average oval edge overhead, occurred on 24% of days from 1996 to 2025 in the GFZ Potsdam record.
- Why does this page point to Moss?
- Horten sits within 15 km of Moss with the same rounded dipole latitude, Kp and dark season, so Glow treats Moss as the main page for both.
Nearby and related
Nearest Glow towns
Horten by month
Region and comparisons