Fairbanks, United States
Tier 1 · needs Kp 2 · Bortle 3. Live answer for Fairbanks tonight.
Crunching NOAA Kp, cloud cover, moon phase and darkness for Minneapolis…
connecting to NOAA SWPC + Open-Meteo…
Aurora sightings over Minneapolis are storm events. The city sits well south of the auroral oval, so a display means the geomagnetic field is doing something unusual — and the Kp number required is correspondingly high.
Minneapolis needs Kp 7. At 45°N it is well south of the auroral oval, so a display here means a genuine storm — but the Upper Midwest is one of the better-placed parts of the United States for it, with flat terrain and frequent cold, clear winter nights.
There is no dark season to plan around at Minneapolis: the sun reaches at least 18° below the horizon on every night of the year, so the sky can be genuinely black in any month you choose. What varies is the length of the usable window and the weather — the northern winter simply gives you more hours of darkness per night to work with.
Daylight is not a limiting factor at Minneapolis: the sun gets 68.5° below the horizon on the darkest night of the year, and there is no stretch of the calendar when the sky fails to go dark. Everything then comes down to cloud and geomagnetic activity.
Head north or west out of the Twin Cities into open farmland; the light dome is large, so give yourself a full thirty minutes of driving.
Face north. Auroral light comes from the oval that rings the magnetic pole, and from Minneapolis that ring lies to the north — so a rooftop, a treeline or a bright shopfront on that side costs you the display no matter how good the forecast is. As for timing, the "best window" figure near the top is the first hour where cloud sits below about 40% during this latitude's darkness.
The table below converts the abstract Kp index into what it actually means from Minneapolis, using its magnetic latitude of 45° and threshold of Kp 7:
| Kp index | What to expect at Minneapolis |
|---|---|
| Kp 0 | Nothing from Minneapolis — the oval stays too far north. Nothing to plan around — save the trip for a stronger forecast. |
| Kp 1 | No display at this latitude; the activity is confined north of Minneapolis. Worth knowing so that a quiet night reads as expected rather than disappointing. |
| Kp 2 | Nothing from Minneapolis — the oval stays too far north. On those nights the forecast at the top of this page will say NO, and that is the honest answer. |
| Kp 3 | No display at this latitude; the activity is confined north of Minneapolis. Nothing to plan around — save the trip for a stronger forecast. |
| Kp 4 | No display at this latitude; the activity is confined north of Minneapolis. Worth knowing so that a quiet night reads as expected rather than disappointing. |
| Kp 5 | Marginal: expect at most a dull arc low in the north, and only away from town. Check the cloud forecast before committing to the drive. |
| Kp 6 | Marginal: expect at most a dull arc low in the north, and only away from town. Give your eyes 20 minutes to adapt before deciding it is a no. |
| Kp 7 | Visible low on the northern horizon from Minneapolis — active arcs, and movement you can see with the naked eye. Have a dark-sky spot picked out before you set off. |
| Kp 8 | Strong showing — tall rays, obvious colour, and curtains that reach well above the horizon. Any genuinely open horizon will do at this level. |
| Kp 9 | A big night: the lights are overhead rather than on the horizon, moving quickly and showing strong colour. These are the nights people travel for. |
The most common reason people in Minneapolis miss a display is not a bad forecast — it is staying inside the city. At Bortle class 8, a Kp 7 event that would be obvious from open country can be completely invisible from a lit street. If the answer above says GO or MAYBE, treat the drive out of town as part of the plan rather than an optional extra.
Five inputs produce the answer at the top of this page, and every one of them is specific to Minneapolis: the NOAA Kp forecast against a threshold of Kp 7 (35% of the score), cloud cover through the night at 44.98°, -93.27° (25%), the moon (15%), astronomical darkness at this latitude (15%), and light pollution at Bortle 8 (10%). The scoring method, its inputs and its failure modes are written up in full on our methodology page. No account, no app, no email address — everything above is computed in your browser from NOAA and Open-Meteo data. Anonymous analytics and Google's advertising script are the only third parties involved, both explained on the privacy page.
Minneapolis crosses the line at Kp 7. Below that the oval does not reach this far northern; above it you are in the range where a clear sky turns into a visible arc. The figure follows from the city's magnetic latitude (45°), which is what the live answer at the top of the page is tested against.
Rarely. Bortle 8 is a bright sky, and the aurora at Kp 7 arrives as a low, faint arc that this much light pollution erases. The practical rule at Minneapolis is that the forecast tells you whether it is worth driving out, not whether you can see it from your window.
Dark enough all year. On the darkest night the sun reaches 68.5° below the horizon, and it clears 18° on every night of the year, so Minneapolis never has a bright-night problem.
The verdict is a weighted composite of five measurements rather than a guess: NOAA's Kp forecast (reliable to roughly 12 hours), cloud cover through the night at Minneapolis's coordinates from Open-Meteo, moon illumination, the dark window computed for this latitude, and Bortle 8 light pollution. Cloud decides more nights than any other input, which is why the page returns LOW or MAYBE far more often than a hopeful GO.
There is no month to rule out at Minneapolis — full astronomical darkness arrives every night of the year, so the calendar never decides the outcome. The night with the clearest forecast is the night to go, and late evening through to about 01:00 is when activity tends to peak.
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