Seattle, WA · magnetic latitude 52.9°
Northern lights in Seattle: tonight’s chance
Seattle needs a real storm and a break in the clouds at the same hour; when both happen, Puget Sound turns green.
Tonight at Seattle, WA
…
Reading the SWPC Kp forecast and the cloud forecast…
| Kp forecast during the dark hours | not yet forecast |
|---|---|
| Kp needed here | 6.4 (G2 moderate) |
| Cloud cover in the dark hours | loading |
| Dark sky (Sun 18° down) | 8:06 PM to 5:44 AM PDT |
| Moon | 13% lit |
| Right now, OVATION (30 to 90 min) | loading or unavailable |
| Magnetic latitude (AACGM) | 52.9° |
Hour by hour, PDT
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 Seattle
- 6.4
- Storm level needed
- G2 (Moderate)
- Kp for aurora overhead
- 6.6
- Most clear dark hours
- September
From Seattle you need a planetary Kp of about 6.4 to see the northern lights, a G2 (Moderate) storm or stronger on the NOAA scale. The city sits at 52.9 degrees magnetic latitude in the AACGM model, lower than its position on the map suggests, because the magnetic pole lies far to the east over Arctic Canada. The aurora reaches overhead only around Kp 6.6. The second obstacle is the sky: the NASA POWER cloud amount ranges from 47% in July to 80% in January, and storm nights from October to March are often lost to Pacific fronts. Taking darkness and clouds together, September and October give the most clear dark hours. The tool below checks tonight's Kp blocks against the National Weather Service sky cover for Seattle, hour by hour.
Why the Pacific Northwest needs a bigger storm
Seattle's latitude, 47.6 degrees north, is close to that of Fargo or Duluth, two cities that see the aurora on modest storms. Seattle needs about 1.3 Kp more than Fargo. The reason is the tilt of Earth's magnetic field: the oval is centred on the magnetic pole in the Canadian Arctic, far to the east of the Pacific coast, so it dips south over the Great Lakes and stays farther north over the Pacific. For Seattle, the realistic opportunities are the G2 and G3 storms of the solar cycle, a few dozen nights a year near maximum and fewer as the cycle declines, as the solar cycle guide explains.
Fighting the Puget Sound clouds
Marine air keeps the lowlands overcast for long stretches between October and March. When a storm is forecast, the useful question is where the clouds will break. Two patterns help: a ridge of high pressure after a front often brings a clear, cold night; and the rain shadow of the Olympics sometimes opens holes around the north Sound and Whidbey Island when Seattle stays grey. The hour strip of the tool, fed by the National Weather Service sky cover, shows when the breaks are expected for the place you type, so it is worth trying a town north of the city as well.
How dark, how clear: one town, one month
Hours of full darkness on the 15th
7.9 h
| Dark sky | 9:07 PM to 5:01 AM |
| Including nautical twilight | 9.2 h |
| Mean cloud amount (NASA POWER) | 54% |
| Clear dark hours on an average night | 3.7 h |
Computed for 2027; the hours move by a few minutes from one year to the next.
Ferries, islands and the north Sound
The islands and peninsulas around Puget Sound give Seattle residents something unusual: dark shorelines facing north within an hour's drive or ferry ride. Each shore has its own skyline, so look at a map before a storm night and pick one that looks north across water rather than toward the Olympic or Cascade foothills.
What it looks like from here
At the edge of Seattle's range, the aurora appears as a pale band low over the northern horizon, often grey to the eye and green or pink on a phone camera. Above Kp 7, rays rise higher and red light from the top of the aurora, more than 300 km up, shows over the north. Only near Kp 6.6 does the display reach overhead. The phone photography guide helps with the faint cases, and the Washington page compares the rest of the state.
Kp needed around Seattle
| Town | Magnetic latitude | Kp to see it | Kp overhead | Storm level |
|---|---|---|---|---|
| Bellingham | 54.0° | 6.0 | 6.0 | G2 (Moderate) |
| Spokane | 53.8° | 6.1 | 6.1 | G2 (Moderate) |
| Wenatchee | 53.1° | 6.4 | 6.5 | G2 (Moderate) |
| Seattle | 52.9° | 6.4 | 6.6 | G2 (Moderate) |
| Yakima | 52.2° | 6.6 | 6.9 | G2 (Moderate) |
| Vancouver | 50.9° | 6.8 | 7.6 | G3 (Strong) |
Darkness and clouds by month in Seattle
| Month | Dark hours | Dark sky, 15th | Mean cloud | Clear dark hours |
|---|---|---|---|---|
| January | 11.5 h | 6:35 PM to 6:02 AM | 80% | 2.3 h |
| February | 10.2 h | 7:16 PM to 5:30 AM | 74% | 2.6 h |
| March | 8.6 h | 8:58 PM to 5:37 AM | 79% | 1.8 h |
| April | 6.5 h | 9:54 PM to 4:23 AM | 75% | 1.6 h |
| May | 4.0 h | 11:04 PM to 3:06 AM | 71% | 1.2 h |
| June | 1.8 h | 12:15 AM to 2:04 AM | 68% | 0.6 h |
| July | 3.1 h | 11:44 PM to 2:47 AM | 47% | 1.6 h |
| August | 5.6 h | 10:25 PM to 4:02 AM | 48% | 2.9 h |
| September | 7.9 h | 9:07 PM to 5:01 AM | 54% | 3.7 h |
| October | 9.7 h | 8:03 PM to 5:47 AM | 68% | 3.1 h |
| November | 11.1 h | 6:20 PM to 5:28 AM | 77% | 2.5 h |
| December | 11.8 h | 6:10 PM to 5:58 AM | 79% | 2.5 h |