Comparison
Sundsvall vs Hudiksvall for the northern lights
Answer
Side by side
| Figure | Sundsvall | Hudiksvall |
|---|---|---|
| Dipole latitude | 61.0° | 60.4° |
| Kp for the oval edge overhead | Kp 3 | Kp 3 |
| Civil night, December 15 | 16.5 h | 16.4 h |
| Dark-season days | 281 | 285 |
| Nights with no civil darkness | 52 | 44 |
| Dark-month cloud, NASA POWER | 71% | 72% |
| Solar midnight, December 15 | 23:46 | 23:47 |
Sundsvall sits at 61.0 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. Hudiksvall sits at 60.4 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 Sundsvall has 16.5 hours of civil night and Hudiksvall 16.4. Across the 15th of each month, Sundsvall is darker in 3 months and Hudiksvall in 5. The widest gap comes in July, when Hudiksvall has 1.3 more hours.
| Month | Sundsvall | Hudiksvall | Difference |
|---|---|---|---|
| January | 15.8 h | 15.6 h | +0.2 h |
| February | 13.3 h | 13.3 h | +0.0 h |
| March | 10.6 h | 10.6 h | +0.0 h |
| April | 7.2 h | 7.4 h | -0.2 h |
| May | 3.1 h | 3.6 h | -0.5 h |
| June | 0.0 h | 0.0 h | +0.0 h |
| July | 0.0 h | 1.3 h | -1.3 h |
| August | 5.9 h | 6.1 h | -0.2 h |
| September | 9.4 h | 9.5 h | -0.1 h |
| October | 12.4 h | 12.4 h | +0.0 h |
| November | 15.1 h | 15.0 h | +0.1 h |
| December | 16.5 h | 16.4 h | +0.1 h |
Season and midnight sun
Sundsvall has no civil darkness from May 26 to July 16, 52 nights in 2026, and its dark season, 4 or more evening hours of civil night, lasts 281 days. Hudiksvall has no civil darkness from May 30 to July 12, 44 nights in 2026, and its dark season, 4 or more evening hours of civil night, lasts 285 days.
Distance, cloud and time zones
The two towns are 75 km apart by great circle. In the dark months both average about 71% cloud in NASA POWER's 2001 to 2020 record. Sundsvall's best month by civil night times clear sky is December. Hudiksvall's best month by civil night times clear sky is December. Time zones: Europe/Stockholm and Europe/Stockholm.
For tonight, open the live pages for Sundsvall and Hudiksvall, which carry the live OVATION cell.
Questions
- Is Sundsvall or Hudiksvall better for the northern lights?
- Sundsvall sits closer to the oval, at 61.0 degrees geomagnetic against 60.4. 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, Sundsvall or Hudiksvall?
- Sundsvall, with 16.5 hours of civil night on December 15 against 16.4 in Hudiksvall.
- What Kp do Sundsvall and Hudiksvall need?
- By SWPC's rule of 66 degrees at Kp 0 and 2 degrees per step, Sundsvall needs about Kp 3 and Hudiksvall Kp 3 for the average oval edge to sit overhead.
- When is it too light for aurora in Sundsvall and Hudiksvall?
- Sundsvall: May 26 to July 16. Hudiksvall: May 30 to July 12.
- Which is clearer, Sundsvall or Hudiksvall?
- Sundsvall, with 71% mean cloud in the months with 4 hours or more of civil night against 72% in Hudiksvall (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.