Comparison
Buffalo vs Greater Sudbury for the northern lights
Answer
Side by side
| Figure | Buffalo | Greater Sudbury |
|---|---|---|
| Dipole latitude | 52.0° | 55.6° |
| Kp for the oval edge overhead | Kp 7 | Kp 6 |
| Civil night, December 15 | 13.8 h | 14.1 h |
| Dark-season days | 365 | 365 |
| Nights with no civil darkness | 0 | 0 |
| Dark-month cloud, NASA POWER | 70% | 65% |
| Solar midnight, December 15 | 00:11 | 00:19 |
Buffalo sits at 52.0 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. Greater Sudbury 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 Buffalo has 13.8 hours of civil night and Greater Sudbury 14.1. Across the 15th of each month, Buffalo is darker in 6 months and Greater Sudbury in 5. The widest gap comes in June, when Buffalo has 0.6 more hours.
| Month | Buffalo | Greater Sudbury | Difference |
|---|---|---|---|
| January | 13.5 h | 13.8 h | -0.3 h |
| February | 12.4 h | 12.5 h | -0.1 h |
| March | 11.0 h | 11.0 h | +0.0 h |
| April | 9.5 h | 9.2 h | +0.3 h |
| May | 8.1 h | 7.7 h | +0.4 h |
| June | 7.4 h | 6.8 h | +0.6 h |
| July | 7.8 h | 7.2 h | +0.6 h |
| August | 9.0 h | 8.6 h | +0.4 h |
| September | 10.5 h | 10.4 h | +0.1 h |
| October | 11.9 h | 12.0 h | -0.1 h |
| November | 13.2 h | 13.4 h | -0.2 h |
| December | 13.8 h | 14.1 h | -0.3 h |
Season and midnight sun
Buffalo has some civil darkness every night of 2026, and clears Glow's 4-hour dark-season bar every evening. Greater Sudbury 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 434 km apart by great circle. In the dark months Greater Sudbury averages 65% cloud and Buffalo 70%, from NASA POWER's 2001 to 2020 record. Buffalo's best month by civil night times clear sky is September. Greater Sudbury's best month by civil night times clear sky is March. Time zones: America/New_York and America/Toronto.
For tonight, open the live pages for Buffalo and Greater Sudbury, which carry the live OVATION cell.
Questions
- Is Buffalo or Greater Sudbury better for the northern lights?
- Greater Sudbury sits closer to the oval, at 55.6 degrees geomagnetic against 52.0. 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, Buffalo or Greater Sudbury?
- Greater Sudbury, with 14.1 hours of civil night on December 15 against 13.8 in Buffalo.
- What Kp do Buffalo and Greater Sudbury need?
- By SWPC's rule of 66 degrees at Kp 0 and 2 degrees per step, Buffalo needs about Kp 7 and Greater Sudbury Kp 6 for the average oval edge to sit overhead.
- When is it too light for aurora in Buffalo and Greater Sudbury?
- Buffalo: never, every night has civil darkness. Greater Sudbury: never, every night has civil darkness.
- Which is clearer, Buffalo or Greater Sudbury?
- Greater Sudbury, with 65% mean cloud in the months with 4 hours or more of civil night against 70% in Buffalo (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.