Northern lights in Seattle tonight
Washington, USA · 54° magnetic latitude · Kp 4–5 threshold
Kp 1 is well below the Kp 4–5 threshold needed for aurora to be visible from Seattle.
7-day outlook for Seattle
Based on CME arrival predictions from NASA DONKI. Arrival times ±6 hours.
auroratonight.space
What Kp is needed here?
Seattle sits at a magnetic latitude of approximately 54°N. The Kp index - a global measure of geomagnetic activity on a scale from 0 (quiet) to 9 (extreme storm), updated every 3 hours - needs to reach Kp 4–5 before the auroral oval expands far enough south to be visible from here.
At Kp 4–5, visibility is possible from Seattle but skies need to be clear and dark. Cloud cover and light pollution remain the main obstacles even when Kp is high enough.
Best dark sky sites near Seattle
Light pollution is the biggest obstacle after cloud cover. These sites give you the best dark northern horizon within reach.
Hurricane Ridge, Olympic National Park
Get directions ↗1.5 hours from downtown Seattle including the ferry crossing from Edmonds to Kingston or Kingston-Edmonds ferry. The summit at 1,640 meters typically sits above the marine cloud layer that covers the Puget Sound lowlands. Olympic National Park holds International Dark Sky Park status, and the north-facing alpine terrain above the tree line gives open sky in all directions. The Hurricane Ridge Road is open year-round on weekends and daily in summer.
Deception Pass State Park
Get directions ↗1 hour north of Seattle on the boundary between Whidbey and Fidalgo Islands. The north-facing coastline on Cranberry Lake and Bowman Bay faces open water toward the San Juan Islands with minimal light pollution. The dramatic bridge spanning the pass makes a distinctive foreground. Light pollution from Anacortes is visible to the east but does not affect the northern horizon.
Leavenworth area (east of the Cascades)
Get directions ↗2.5 hours from Seattle via US-2 through Stevens Pass. The Cascade rain shadow drops cloud cover rates dramatically - Leavenworth averages around 300 clear nights per year versus Seattle's 160. Bortle 3-4 conditions in the Wenatchee National Forest north of town. The north-facing terrain above the Wenatchee River valley gives clear northern sightlines, and the mountain backdrop makes for strong aurora compositions when active.
Best time to see the northern lights in Seattle
Seattle's aurora season runs from late September through to March, when nights are long enough for truly dark skies. The equinox months, September and March, bring a natural boost in geomagnetic activity, making them statistically the best of the season. Summer months bring too much twilight for aurora to be visible at this latitude.
Activity peaks around the September and March equinoxes, when Earth's magnetic field geometry is most favourable for coupling with the solar wind. Events during these two windows tend to produce the strongest displays of the year for observers at Seattle's latitude.
April through August brings persistent astronomical twilight that washes out aurora completely. Even strong events (Kp 6+) remain invisible during this period because the sky never gets dark enough.
Up to 8 locations
How often does the aurora appear in Seattle?
Average nights per month the Kp reached Seattle's threshold of 4+, from 15 years of geomagnetic data (2010–2024).
Counts the Kp 4+ threshold only - cloud cover and local darkness are not included.
Kp data: GFZ German Research Centre for Geosciences, CC BY 4.0
Plan your trip to Seattle
Best window
The August to October window averages 15 aurora nights - the strongest consecutive stretch of the year.
How long to stay
For your best chance in March, plan at least 9 nights.
Related pages
Northern Lights USA
USA-wide aurora forecast hub.
Read →Northern Lights Washington State
Washington State aurora forecast, from Seattle to the Cascades.
Read →Northern Lights Oregon
Oregon aurora forecast and dark sky locations.
Read →Northern Lights Bozeman Tonight
Bozeman - Montana dark sky with more clear nights per year than Seattle.
Read →What Is the Kp Index?
What Kp 4-5 means for aurora viewing at 54° magnetic latitude.
Read →Aurora photographs from Seattle
Real photos sourced from Wikimedia Commons.
Aurora over Seattle 
Aurora over Seattle 
Aurora over Seattle 
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