Aurora for Portland, OR
No aurora expected in Portland tonight
Kp threshold for Portland: ~3. Tonight's forecast peak: 4.0.
Storm strengthKp 4.0 — Unsettled
Kp is a 0–9 scale of geomagnetic storm strength — the higher it is, the farther south the aurora reaches. Your latitude (46°N) needs roughly Kp 3.
Aurora reaches61°N (you: 45.5°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 starts11:11 PM
Data as of Jul 21, 2026
Coming Up
Seeing the northern lights from Portland, OR
Portland sits at about 45.5°N. The aurora becomes visible here only when a geomagnetic storm expands the auroral oval far enough south to reach your latitude — roughly Kp 3 or stronger. At your latitude that happens during moderate storms several times a year.
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. This far south the aurora usually shows as a low green or red glow near the horizon rather than overhead curtains — a camera often captures it before your eyes do.
A bright moon or clouds will wash out a faint display, so the best nights pair a strong storm with clear, dark skies. Check back here on active nights for the current odds in Portland.