Checking the live aurora model…
The aurora follows Earth's magnetic field, not the map grid. Saint-Jean-sur-Richelieu sits at 54.6° geomagnetic latitude, and NOAA's table says the aurora reaches that line at Kp 6 — a G2 storm, which happens on ~360 days per 11-year solar cycle.
| Kp index | Reaches down to | How often |
|---|---|---|
| Kp 3 | 60.4° geomagnetic | quiet to unsettled conditions |
| Kp 4 | 58.3° geomagnetic | quiet to unsettled conditions |
| Kp 5 | 56.3° geomagnetic | G1 · ~900 days per 11-year solar cycle |
| Kp 6 | 54.2° geomagnetic | G2 · ~360 days per 11-year solar cycle |
| Kp 7 | 52.2° geomagnetic | G3 · ~130 days per 11-year solar cycle |
| Kp 8 | 50.1° geomagnetic | G4 · ~60 days per 11-year solar cycle |
| Kp 9 | 48.1° geomagnetic | G5 · about 4 days per 11-year solar cycle |
Storm frequencies are NOAA's published figures for the G-scale, averaged over an 11-year solar cycle.
Even when the Kp is high enough, street lighting can hide a low, faint aurora. Our light pollution map starts on Saint-Jean-sur-Richelieu and finds the darkest spots within driving distance:
Yes, but only during a geomagnetic storm. Saint-Jean-sur-Richelieu sits at 54.6° geomagnetic latitude, so the aurora reaches it at a Kp index of 6 — a G2 storm, which NOAA records on ~360 days per 11-year solar cycle. The live Kp index and the three-day forecast are at the top of this page.
The aurora follows Earth's magnetic field, and the magnetic pole is not at the geographic pole — it sits near 80.7°N, 72.7°W. That is why Saint-Jean-sur-Richelieu at 45.3° on the map behaves like 54.6° for the aurora. It also means places at the same map latitude can need very different Kp values: northern Europe sees the aurora far more easily than the same latitude in Siberia.
Activity usually peaks around local magnetic midnight, roughly 22:00–02:00, but a substorm can start any time it is dark. At this latitude the aurora normally appears low on the northern horizon, so you need a clear view north and as little light as possible.
Yes. A bright moon washes out a faint aurora the same way city lights do. The moon tile above shows tonight's phase and illumination — under 25% is a good dark sky, over 65% will hide anything but a strong display.
The Kp index, the three-day forecast and the OVATION aurora model come from the NOAA Space Weather Prediction Center — U.S. government works in the public domain, refreshed here every 30 minutes. The Kp threshold for Saint-Jean-sur-Richelieu is calculated from its geomagnetic latitude using NOAA's published table. Cloud cover is not part of this page — check your local weather forecast too.