Juneau, AK · magnetic latitude 61.0°
Northern lights in Juneau: tonight’s chance
Juneau is magnetically farther north than its map position suggests; its rainforest climate is the real hurdle.
Tonight at Juneau, AK
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Reading the SWPC Kp forecast and the cloud forecast…
| Kp forecast during the dark hours | not yet forecast |
|---|---|
| Kp needed here | 2.5 |
| Cloud cover in the dark hours | loading |
| Dark sky (Sun 18° down) | 8:08 PM to 5:19 AM AKDT |
| Moon | 14% lit |
| Right now, OVATION (30 to 90 min) | loading or unavailable |
| Magnetic latitude (AACGM) | 61.0° |
Hour by hour, AKDT
7 PM
Kp –
– ☁
No
8 PM
Kp –
– ☁
No
9 PM
Kp –
– ☁
No
10 PM
Kp –
– ☁
No
11 PM
Kp –
– ☁
No
12 AM
Kp –
– ☁
No
1 AM
Kp –
– ☁
No
2 AM
Kp –
– ☁
No
3 AM
Kp –
– ☁
No
4 AM
Kp –
– ☁
No
5 AM
Kp –
– ☁
No
6 AM
Kp –
– ☁
No
Rules checked · Built by Radif Partners · How the answer works
- Kp to see it from Juneau
- 2.5
- Storm level needed
- no storm
- Kp for aurora overhead
- 2.5
- Most clear dark hours
- February
Juneau needs a planetary Kp of about 2.5 to see the northern lights, almost the same as Anchorage, even though it lies about three degrees of latitude farther south: in the AACGM model Alaska's capital sits at 61.0 degrees magnetic latitude, because the magnetic pole lies in northern Canada and the panhandle tucks toward it. On a geomagnetic basis, then, an ordinary active night can bring aurora. The difficulty is the weather. Juneau lies in a temperate rainforest, and the NASA POWER cloud amount never falls below 74% in any month, peaking at 81% in July. Full darkness lasts 12.4 hours in mid-December and disappears in summer. The months with the most clear dark hours are February, December and January, when a cold, dry spell can open the sky.
Magnetically north, meteorologically wet
Look at a map and Juneau seems far from the aurora's heartland, at the bottom of the panhandle, closer to Seattle than to Fairbanks by road distance. The magnetic picture is different. The magnetic pole sits in the Canadian Arctic, and Southeast Alaska bends toward it, which gives Juneau a magnetic latitude of 61.0 degrees. On the Kp scale it needs 2.5, practically the same as Anchorage. If Juneau had Fairbanks' skies, it would be a first-rate place to watch.
It does not. Moist Pacific air rises against the Coast Mountains behind the city, and the rain and low cloud that make the Tongass a rainforest also make clear nights the exception. In the NASA POWER averages the clearest month, May, is still at 74% cloud amount. That is why the cloud line of the tool matters more here than the Kp line: when the National Weather Service forecasts a clearing, check the Kp, and if it is anywhere near 2.5, go out.
How dark, how clear: one town, one month
Hours of full darkness on the 15th
10.1 h
| Dark sky | 7:08 PM to 5:13 AM |
| Including nautical twilight | 11.6 h |
| Mean cloud amount (NASA POWER) | 75% |
| Clear dark hours on an average night | 2.5 h |
Computed for 2027; the hours move by a few minutes from one year to the next.
Steep horizons
Juneau's other constraint is its relief. Mount Juneau and Mount Roberts rise straight above downtown, and the channel is narrow, so the low northern sky where a moderate aurora sits is hidden from many streets. The Mendenhall valley opens more sky, and the shoreline north toward Auke Bay faces the water. When the Kp climbs well above the threshold, the display rises higher and the mountains matter less. Winter brings another pattern worth knowing: after a front passes, cold air from the Interior sometimes spills through the mountain passes and clears the sky for a night or two, often with strong wind. Those outflow nights are among the clearest of the season, and they are the ones to check the Kp forecast for. In the hour strip of the tool, a run of hours under 30% cloud is rare enough in Juneau to be worth acting on even when the answer is only maybe. For the rest of the state see the Alaska page, and for a comparison with the dry Interior the Fairbanks page.
Kp needed around Juneau
| Town | Magnetic latitude | Kp to see it | Kp overhead | Storm level |
|---|---|---|---|---|
| Utqiaġvik | 70.5° | 0.0 | 0.0 | no storm |
| Fairbanks | 65.2° | 0.4 | 0.4 | no storm |
| Kotzebue | 65.1° | 0.4 | 0.4 | no storm |
| Nome | 62.3° | 1.9 | 1.9 | no storm |
| Anchorage | 61.1° | 2.4 | 2.4 | no storm |
| Juneau | 61.0° | 2.5 | 2.5 | no storm |
| Bethel | 58.8° | 3.6 | 3.6 | no storm |
| Ketchikan | 58.6° | 3.7 | 3.7 | no storm |
Darkness and clouds by month in Juneau
| Month | Dark hours | Dark sky, 15th | Mean cloud | Clear dark hours |
|---|---|---|---|---|
| January | 11.9 h | 6:09 PM to 6:04 AM | 80% | 2.4 h |
| February | 10.1 h | 7:08 PM to 5:13 AM | 75% | 2.5 h |
| March | 7.7 h | 9:16 PM to 4:55 AM | 76% | 1.9 h |
| April | 3.7 h | 11:06 PM to 2:47 AM | 75% | 0.9 h |
| May | none | – | 74% | 0.0 h |
| June | none | – | 81% | 0.0 h |
| July | none | – | 81% | 0.0 h |
| August | none | – | 79% | 0.0 h |
| September | 6.4 h | 9:39 PM to 4:06 AM | 81% | 1.2 h |
| October | 9.3 h | 8:04 PM to 5:23 AM | 81% | 1.8 h |
| November | 11.4 h | 5:59 PM to 5:26 AM | 80% | 2.3 h |
| December | 12.4 h | 5:39 PM to 6:06 AM | 80% | 2.5 h |