Aurora Borealis in Great Falls
United States · 47.50°, -111.30° · geomagnetic 54.4° · needs Kp 7
Tonight in Great Falls
1%
Peak chance of a visible display tonight, from the same model the Revon app runs. Great Falls needs Kp 7 to see anything at all, and tonight the forecast peaks at Kp 4.7. Short of the threshold, which is what most nights look like here.
Updated 2026-08-02 20:20 UTC
The next 30 nights in Great Falls
Every night to come, scored the same way as tonight. The best of the open week is Sunday 2 Aug at 1%. Not one of the seven reaches the Kp 7 that Great Falls needs, which is normal rather than unlucky — it averages 3.2 viable nights a year. The 23 nights past the seven-day window move with the 27-day solar rotation and are updated daily in the app.
Nights 8–30 unlock in the Revon app
See all 30 nights for Great Falls
Revon aurora model over the NOAA Kp forecast and 27-day outlook
How often the aurora borealis reaches Great Falls
3.2 nights a year, averaged across 10.0 years of records
| Storm level | Nights / year |
|---|---|
| Kp 4 | 83.4 |
| Kp 5 | 28.7 |
| Kp 6 | 9.3 |
| Kp 7 | 3.2 |
| Kp 8 | 1.2 |
NOAA planetary Kp, 2016-04-02 to 2026-03-30
Wait for an alert; do not book a week
At Kp 7, Great Falls needs a severe geomagnetic storm before anything shows above the northern horizon. Storms that size arrive a handful of times per solar cycle and announce themselves a day or two ahead. Watching for one beats picking dates and hoping.
Hours of true darkness, month by month
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 11.5 | 10.3 | 8.8 | 6.6 | 4.1 | 1.9 | 3.1 | 5.7 | 8.0 | 9.9 | 11.2 | 11.8 |
Solar declination and hour angle at −18°
Getting clear of the light
The sky over Great Falls reads Bortle 4. Getting clear of the built-up area makes a visible difference on a marginal night.
- 4 km east → Bortle 4
- 4 km east → Bortle 4
Falchi 2016 World Atlas (DOI: 10.5880/GFZ.1.4.2016.001)
The months that actually deliver
Counting only nights that were both stormy enough and dark enough, May, September and August came out ahead in Great Falls. That is storm season and darkness overlapping — the equinoxes tend to be geomagnetically active, and the nights are already long by then.
Darkest nights of the coming year
A bright moon washes out a weak display as effectively as street lighting. These new moons fall inside the Great Falls viewing season.
- 13 Aug 2026
- 11 Sep 2026
- 11 Oct 2026
- 09 Nov 2026
- 09 Dec 2026
- 07 Jan 2027
- 06 Feb 2027
Where it is close to a certainty
If you would rather plan a trip than wait for a storm, the nearest place with genuinely frequent aurora is Yellowknife, 1,674 km north in Canada.
| Great Falls | Yellowknife | |
|---|---|---|
| Kp needed | 7 | 3 |
| Nights per year | 3.2 | 171.4 |
| Geomagnetic latitude | 54.4° | 68.6° |
Confirmed reports from this area
43 verified sightings were logged within 300 km of Great Falls between 2015-01-01 and 2016-12-31. Rare is not the same as impossible.
Aurorasaurus verified positive reports
Where the horizon opens up near Great Falls
The display sits low on the northern horizon, so what beats a better forecast is open ground facing that way. Height gets you above the town glow; water gives you an unbroken skyline. These are within a short drive of Great Falls.
- Gallatin Park — park3.1 km north
- Westside Viaduct Park — park3.1 km west-north-west
- Smelter Hill — mountain3.3 km north-east
- Hill Fifty-seven — mountain3.8 km north-west
- Steamboat Island — island5.6 km north-east
- Horseshoe Lake — lake10.2 km west
Places from GeoNames (CC BY 4.0)
What to do with the daylight
Aurora watching is a night job, and in winter that leaves a short, bright day to fill. Close to Great Falls you will find KQDI-AM (Great Falls), KGPR-FM (Great Falls) and KLFM-FM (Great Falls), and for a day when the cloud sits low, C M Russell Museum, Cascade County Historical Society Museum and Paris Gibson Square Museum of Art are indoors and near by.
Keep the daylight loose: the sky decides the evening, and the forecast can turn within a few hours.
Places from GeoNames (CC BY 4.0)
Where to stay
Anywhere on the outskirts of Great Falls will do; what matters is being able to step outside and check the sky without a drive first.
- Quality Inn Ponderosa 0.6 km from the centre
- O'haire Motor Inn 0.6 km from the centre
- Staybridge Suites Great Falls 1.5 km from the centre
- Great Falls - Days Inn 2.3 km from the centre
- La Quinta Inn And Suites Great Falls 0.6 km from the centre
- Esa Great Falls-Missouri River 0.7 km from the centre
Places from GeoNames (CC BY 4.0) — confirm before booking
The last nights it was visible here
Nights in the last decade when the storm was strong enough for Great Falls and the sky was dark enough to show it.
| Date | Peak |
|---|---|
| 2026-03-20 | Kp 7.0 |
| 2026-01-20 | Kp 7.67 |
| 2026-01-19 | Kp 8.67 |
| 2025-11-12 | Kp 7.33 |
| 2025-11-11 | Kp 8.67 |
NOAA planetary Kp
Know when it is worth going outside
Revon watches the Great Falls forecast and pushes an alert when the odds for tonight clear your threshold — no checking, no guessing.
Common questions about the aurora borealis in Great Falls
Can you see the aurora borealis from Great Falls?
Yes. On the last 10.0 years of NOAA Kp records, Great Falls had about 3.2 nights a year when the storm was strong enough and the sky dark enough at the same time.
What Kp index do you need to see the aurora borealis in Great Falls?
Kp 7. Great Falls sits at geomagnetic latitude 54.4°, and the auroral oval only reaches that far from the pole once activity hits Kp 7. Storms that size occur about 3.2 nights a year.
When is the best time of year to see the aurora borealis in Great Falls?
May, September and August. Those months scored highest once both conditions are counted together: geomagnetic activity and enough hours of real darkness.
Where can you escape the light pollution near Great Falls?
The centre of Great Falls reads Bortle 4. The nearest sky at Bortle 4 is about 4 km east. On a marginal night that drive matters more than the forecast does.
Where is the nearest place to Great Falls with reliable aurora borealis?
Yellowknife, Canada — 1,674 km north. It needs only Kp 3 and averages 171.4 viable nights a year against 3.2 in Great Falls.
Nearby towns
Forecasts for places within reach of Great Falls.