Comparison
Uppsala vs Sollentuna for the northern lights
Answer
Side by side
| Figure | Uppsala | Sollentuna |
|---|---|---|
| Dipole latitude | 58.5° | 58.1° |
| Kp for the oval edge overhead | Kp 4 | Kp 4 |
| Civil night, December 15 | 16.0 h | 15.9 h |
| Dark-season days | 301 | 305 |
| Nights with no civil darkness | 0 | 0 |
| Dark-month cloud, NASA POWER | 77% | 77% |
| Solar midnight, December 15 | 23:45 | 23:43 |
Uppsala sits at 58.5 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. Sollentuna sits at 58.1 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.
Civil night month by month
On December 15 Uppsala has 16.0 hours of civil night and Sollentuna 15.9. Across the 15th of each month, Uppsala is darker in 2 months and Sollentuna in 6. The widest gap comes in June, when Sollentuna has 0.6 more hours.
| Month | Uppsala | Sollentuna | Difference |
|---|---|---|---|
| January | 15.3 h | 15.3 h | +0.0 h |
| February | 13.1 h | 13.1 h | +0.0 h |
| March | 10.7 h | 10.7 h | +0.0 h |
| April | 7.7 h | 7.8 h | -0.1 h |
| May | 4.5 h | 4.7 h | -0.2 h |
| June | 1.2 h | 1.8 h | -0.6 h |
| July | 3.2 h | 3.4 h | -0.2 h |
| August | 6.6 h | 6.7 h | -0.1 h |
| September | 9.6 h | 9.7 h | -0.1 h |
| October | 12.3 h | 12.3 h | +0.0 h |
| November | 14.7 h | 14.6 h | +0.1 h |
| December | 16.0 h | 15.9 h | +0.1 h |
Season and midnight sun
Uppsala has some civil darkness every night of 2026, and its dark season, 4 or more evening hours of civil night, lasts 301 days. Sollentuna has some civil darkness every night of 2026, and its dark season, 4 or more evening hours of civil night, lasts 305 days.
Distance, cloud and time zones
The two towns are 51 km apart by great circle. In the dark months both average about 77% cloud in NASA POWER's 2001 to 2020 record. Uppsala's best month by civil night times clear sky is November. Sollentuna's best month by civil night times clear sky is November. Time zones: Europe/Stockholm and Europe/Stockholm.
For tonight, open the live pages for Uppsala and Sollentuna, which carry the live OVATION cell.
Questions
- Is Uppsala or Sollentuna better for the northern lights?
- Uppsala sits closer to the oval, at 58.5 degrees geomagnetic against 58.1. 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, Uppsala or Sollentuna?
- Uppsala, with 16.0 hours of civil night on December 15 against 15.9 in Sollentuna.
- What Kp do Uppsala and Sollentuna need?
- By SWPC's rule of 66 degrees at Kp 0 and 2 degrees per step, Uppsala needs about Kp 4 and Sollentuna Kp 4 for the average oval edge to sit overhead.
- When is it too light for aurora in Uppsala and Sollentuna?
- Uppsala: never, every night has civil darkness. Sollentuna: never, every night has civil darkness.
- Which is clearer, Uppsala or Sollentuna?
- Uppsala, with 77% mean cloud in the months with 4 hours or more of civil night against 77% in Sollentuna (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.