Northern Lights forecast
Aurora chances ride on the Kp index, a 0-9 measure of geomagnetic activity. The higher it climbs, the farther south the lights reach — Alaska sees them at Kp 1, the northern-tier states need Kp 5-6, and only major storms push them to the mid-latitudes. Dark, clear skies and an open northern horizon are essential.
🧭 Kp index now
1.7
Quiet
Scale 0-9 · updated 20:19
🌙 Peak in the next 24h
1.7
Quiet
Expected peak Wed 30/9 20:00
Good chancePossibleLow chanceUnlikelyAurora zone (Kp 1.7)
Who can see the aurora tonight?
At Kp 1.7 under clear skies
Fairbanks, AK
64.8°N
Possible
Yellowknife, NT
62.5°N
Slight chance
Anchorage, AK
61.2°N
Slight chance
Whitehorse, YT
60.7°N
Slight chance
Juneau, AK
58.3°N
Slight chance
Edmonton, AB
53.6°N
Unlikely
Saskatoon, SK
52.1°N
Unlikely
Calgary, AB
51.1°N
Unlikely
Winnipeg, MB
49.9°N
Unlikely
Seattle, WA
47.6°N
Unlikely
Great Falls, MT
47.5°N
Unlikely
Fargo, ND
46.9°N
Unlikely
Duluth, MN
46.8°N
Unlikely
Minneapolis, MN
45.0°N
Unlikely
Bangor, ME
44.8°N
Unlikely
Green Bay, WI
44.5°N
Unlikely
Buffalo, NY
42.9°N
Unlikely
Chicago, IL
41.9°N
Unlikely
We weigh tonight's Kp against how far north each city sits. What we can't weigh is your local sky — clouds and city glow decide the rest, so peek at
the cloud layer on radar first.
3-day Kp forecast
3-hour intervals · NOAA SWPC
Aurora-spotting tips
- Escape city glow — even 20 miles out makes a difference.
- Find an open view to the north.
- Check the cloud forecast — clear skies are non-negotiable.
- Prime window: roughly 10 PM–2 AM local.
- Give your eyes 15-20 minutes to fully dark-adapt.
- Your phone camera on night mode will spot faint aurora first.
What is the Kp index?
Kp gauges disturbance of Earth's magnetic field from 0 to 9. Around
Kp 4-5, aurora reaches the Canadian border states — Washington, Montana, the Dakotas, Minnesota. At
Kp 6-7 it can dip to Oregon, Iowa and New York, and historic storms (
Kp 8-9) have lit skies as far south as Texas. Values refresh every three hours.