Aurora for Bismarck, ND
No aurora expected in Bismarck tonight
Kp threshold for Bismarck: ~5. Tonight's forecast peak: 3.3.
Storm strengthKp 3.3 — Unsettled
Kp is a 0–9 scale of geomagnetic storm strength — the higher it is, the farther south the aurora reaches. What matters is geomagnetic latitude, not the latitude on a map: Bismarck sits at 54.8° geomagnetic (vs 46.8°N on the map), which needs about Kp 5.
Aurora reaches64°N (you: 46.8°N)
The southern edge of where the aurora is overhead tonight. You can sometimes catch it low on the northern horizon a few degrees farther south.
- Cloud cover0%
- Moon50% brightness
- Dark sky starts8:33 PM
Data as of Oct 18, 2026
Coming Up
Seeing the northern lights from Bismarck, ND
The number that decides whether Bismarck sees an aurora is not the latitude on a map. The auroral oval is centred on the geomagnetic pole, which sits over Arctic Canada near 80.7°N, 72.7°W — well off the geographic pole. Bismarck sits at 46.8°N on a map but about 54.8° geomagnetic, roughly 8.0° closer to the aurora than the map suggests.
That offset is why two cities on the same parallel can have very different odds. Portland, Maine and Boise, Idaho are both near 43.6°N, but Portland sits about 3° higher in geomagnetic latitude — close to a full Kp step — so the same storm that puts a glow on Portland's horizon can leave Boise with nothing.
For Bismarck the practical threshold is about Kp 5, which happens roughly monthly around solar maximum. At that strength expect a low glow along the northern horizon — often easier for a camera than the eye. Stronger storms push the oval further south and lift the display higher up the sky.
When a storm is in range, find a spot with a clear, dark view of the northern horizon, away from city lights, after evening twilight ends. A bright moon or clouds will wash out a faint display, so the best nights pair a strong storm with clear, dark skies.