Comparison
Seattle vs Kelowna for the northern lights
Answer
Side by side
| Figure | Seattle | Kelowna |
|---|---|---|
| Dipole latitude | 53.0° | 55.6° |
| Kp for the oval edge overhead | Kp 7 | Kp 6 |
| Civil night, December 15 | 14.3 h | 14.5 h |
| Dark-season days | 365 | 365 |
| Nights with no civil darkness | 0 | 0 |
| Dark-month cloud, NASA POWER | 68% | 66% |
| Solar midnight, December 15 | 00:05 | 00:53 |
Seattle sits at 53.0 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 7. Kelowna sits at 55.6 degrees geomagnetic. By SWPC's rule the average oval edge is overhead at Kp 6, and aurora is usually visible on the northern horizon at G1 (Kp 5) or less.
Civil night month by month
On December 15 Seattle has 14.3 hours of civil night and Kelowna 14.5. Across the 15th of each month, Seattle is darker in 7 months and Kelowna in 5. The widest gap comes in May, when Seattle has 0.4 more hours.
| Month | Seattle | Kelowna | Difference |
|---|---|---|---|
| January | 13.9 h | 14.1 h | -0.2 h |
| February | 12.5 h | 12.6 h | -0.1 h |
| March | 11.0 h | 10.9 h | +0.1 h |
| April | 9.1 h | 8.9 h | +0.2 h |
| May | 7.5 h | 7.1 h | +0.4 h |
| June | 6.5 h | 6.1 h | +0.4 h |
| July | 7.0 h | 6.6 h | +0.4 h |
| August | 8.5 h | 8.3 h | +0.2 h |
| September | 10.3 h | 10.2 h | +0.1 h |
| October | 12.0 h | 12.1 h | -0.1 h |
| November | 13.5 h | 13.7 h | -0.2 h |
| December | 14.3 h | 14.5 h | -0.2 h |
Season and midnight sun
Seattle has some civil darkness every night of 2026, and clears Glow's 4-hour dark-season bar every evening. Kelowna has some civil darkness every night of 2026, and clears Glow's 4-hour dark-season bar every evening.
Distance, cloud and time zones
The two towns are 328 km apart by great circle. In the dark months Kelowna averages 66% cloud and Seattle 68%, from NASA POWER's 2001 to 2020 record. Seattle's best month by civil night times clear sky is September. Kelowna's best month by civil night times clear sky is September. Time zones: America/Los_Angeles and America/Vancouver.
For tonight, open the live pages for Seattle and Kelowna, which carry the live OVATION cell.
Questions
- Is Seattle or Kelowna better for the northern lights?
- Kelowna sits closer to the oval, at 55.6 degrees geomagnetic against 53.0. 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, Seattle or Kelowna?
- Kelowna, with 14.5 hours of civil night on December 15 against 14.3 in Seattle.
- What Kp do Seattle and Kelowna need?
- By SWPC's rule of 66 degrees at Kp 0 and 2 degrees per step, Seattle needs about Kp 7 and Kelowna Kp 6 for the average oval edge to sit overhead.
- When is it too light for aurora in Seattle and Kelowna?
- Seattle: never, every night has civil darkness. Kelowna: never, every night has civil darkness.
- Which is clearer, Seattle or Kelowna?
- Kelowna, with 66% mean cloud in the months with 4 hours or more of civil night against 68% in Seattle (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.