Northern lights in Alta in December
78%
of 4-night stays in December saw the northern lights at least once, by our estimate. On any one night the chance was 34%. December is a good month in Alta, though January (88%) was better.
How long to stay in December
Chance of at least one good night, by length of stay, Alta in December, 2015–2025. 4 nights got you to about 3 in 4.
In a typical December, the longest run of nights without a single clear, dark hour was 5 nights. A stay shorter than that can fall entirely into one cloudy spell.
Week by week in December (4-night stay)
- 2 Dec – 8 Dec75%
- 9 Dec – 15 Dec78%
- 16 Dec – 22 Dec79%
- 23 Dec – 29 Dec77%
December in Alta, year by year
Good nights in December, each year 2015–2025. The typical December had 11 good nights; the worst, 2017, had 6 and the best, 2023, had 15. 2023–2025, around the solar maximum, averaged 14 against 9 before.
A good night = at least one hour that was dark (sun below −12°), mostly clear (NASA POWER cloud data, calibrated on FMI weather stations) and had a Kp index at or above the Kp 0.9 that Alta needs (GFZ Potsdam). These are estimates, not sightings. How it works
Other destinations in December
Alta ranks 5th of 21 popular aurora destinations for December (4-night stays, 2015–2025).
Yellowknife
97%Churchill
92%Kilpisjärvi
80%Fairbanks
79%Lofoten
72%Abisko
71%Aurora tours in Alta in December
A guide with a car can drive to wherever the clouds break. With cloudy spells of 5 nights in a typical December, that matters here. Booking for your first night leaves the rest of the stay to try again if it's cloudy.
Alta in December: questions
December is a good month in Alta, though January (88%) was better. In 2015–2025, 78% of 4-night stays in December saw the northern lights at least once, and an average December had 11 good nights (clear, dark and with auroras strong enough) out of 31. These are estimates from NASA cloud records and the Kp index, not sightings.
2 nights gave 56%, 4 nights gave 78%, 7 nights gave 94% odds of at least one good night in December (2015–2025). For about 3-in-4 odds, plan 4 nights or more. In a typical December, the longest run of nights without a single clear, dark hour was 5 nights. A stay shorter than that can fall entirely into one cloudy spell.
About 16.0 hours a night with the sun more than 12° below the horizon, which is dark enough for faint auroras. Of those, 2.4 hours a night were mostly clear on average, and 13 nights in an average December had at least one clear, dark hour.
Auroras can appear any time it's dark, but activity usually peaks around midnight, roughly 22:00 to 02:00. With about 16.0 hours of darkness a night in December, start looking as soon as it's dark and stay out past midnight if you can. The live forecast shows tonight's best hour.