Aurora Borealis in Thunder Bay
Canada · 48.38°, -89.25° · geomagnetic 57.3° · needs Kp 7
Tonight's aurora forecast for Thunder Bay
27%
Peak chance of a visible display tonight, from the same model the Revon app runs. Thunder Bay needs Kp 7 to see anything at all, and tonight the forecast peaks at Kp 5.0. Short of the threshold, which is what most nights look like here.
Get the full 30-night forecast in Revon
Updated 2026-09-08 10:35 UTC
Local aurora guide for Thunder Bay
Thunder Bay is located at 57.3° geomagnetic latitude. Auroras are typically visible at this latitude during periods of high geomagnetic activity, specifically when the Kp index reaches 7 or higher.
On average, there are about 3.2 nights per year in Thunder Bay where conditions are suitable for aurora viewing, based on historical geomagnetic data spanning from 2016 to 2026.
The best months for aurora viewing in Thunder Bay are May, September, and August. These months offer a good balance of darkness and potential aurora activity.
Thunder Bay experiences a Bortle 3 sky, indicating very dark conditions. Areas 13 km north of the city also maintain Bortle 3 conditions.
Several locations offer varied horizons. Boulevard Lake, located 9.5 km north-northeast, is a lake. Bare Point, 9.8 km north-east, is a headland. Green Bay and Green Bay Beach, both 15.8 km north-east, are a bay and a beach respectively. Melancon Point, also 15.8 km north-east, is another headland.
Geographic features near Thunder Bay include Boulevard Lake, a lake situated 9.5 km north-northeast. Bare Point, a headland, is located 9.8 km north-east.
Further north-east, 15.8 km from the city, are Green Bay, a bay, and Green Bay Beach, a beach. Melancon Point, also a headland, is found at the same distance.
Between 2016 and 2026, there were approximately 3.2 nights per year suitable for aurora viewing in Thunder Bay. The historical record spans from April 2, 2016, to March 30, 2026.
Aurorasaurus has recorded 77 verified reports within 300 km of Thunder Bay between January 1, 2015, and December 31, 2016.
Notable qualifying nights within the record span include March 20, 2026 (Kp 7.0), January 20, 2026 (Kp 7.67), January 19, 2026 (Kp 8.67), November 12, 2025 (Kp 7.33), and November 11, 2025 (Kp 8.67).
Sources: Revon location dataset · Revon analysis of NOAA planetary Kp · Falchi 2016 World Atlas of artificial night sky brightness · GeoNames (CC BY 4.0) · Aurorasaurus verified positive reports
Know when it is worth going outside
Revon watches the Thunder Bay forecast and pushes an alert when the odds for tonight clear your threshold — no checking, no guessing.
Nearby towns
Forecasts for places within reach of Thunder Bay.