Canada · Aurora borealis
Is the aurora visible in Thunder Bay tonight?
Right now
Not tonight.
Kp is 0.0. Thunder Bay needs Kp 7+ for the oval overhead — right now it’s not reaching Thunder Bay.
Tonight's peak is forecast around Kp 5.3 (Minor storm). The forecast still depends on darkness, cloud and the moon at your exact spot.
Reliable about 30 minutes ahead — cloud decides the rest.
Thunder Bay only catches the aurora during strong geomagnetic storms — it needs roughly Kp 7+ for the northern lights to come into view. Here's tonight's live space weather and how to plan around it.
How to see the aurora from Thunder Bay
Face north and find a clear, low horizon in that direction. Everything else — dark skies, adapted eyes, the camera trick — is the same anywhere on Earth, so it lives in the how to photograph the aurora guide.
When can you see the northern lights in Thunder Bay?
Aurora season in Thunder Bay runs roughly September – March. Here the months that pay off are September, May, and March — the table below shows why. See the full best time to see the aurora guide for the season in detail.
Thunder Bay by the numbers
Between Sep 1, 2025 and Aug 31, 2026, Thunder Bay had 365 nights dark enough for the aurora, and the planetary Kp reached the Kp 7+ this place needs on 9 of them. Averaged over 2015–2024 and this location's cloud cover, that works out to about 2 aurora-possible nights a year, most of them in September, May, and March.
| Month | Dark hours per night | Dark nights | Average cloud cover | Aurora-possible nights |
|---|---|---|---|---|
| January | 14 h | 31 | 70% | 0 |
| February | 12.8 h | 28 | 61% | 0 |
| March | 11 h | 31 | 60% | <1 |
| April | 9.3 h | 30 | 65% | <1 |
| May | 7.3 h | 31 | 60% | <1 |
| June | 6.3 h | 30 | 61% | <1 |
| July | 7 h | 31 | 51% | 0 |
| August | 8.5 h | 31 | 56% | <1 |
| September | 10.3 h | 30 | 58% | <1 |
| October | 12 h | 31 | 69% | <1 |
| November | 13.8 h | 30 | 76% | <1 |
| December | 14.3 h | 31 | 76% | 0 |
Sources: the sun's geometry (dark = at least 6° below the horizon), GFZ Potsdam's Kp index 2015–2024 (CC BY 4.0), ERA5 cloud cover via Open-Meteo (the table shows the monthly mean; the estimate counts days that were not overcast). An estimate for comparing places and months, not a forecast — how we estimate this.
Where it’s reliable
