Aurora Borealis in West Lake Sammamish
United States · 47.58°, -122.10° · geomagnetic 53.1° · needs Kp 7
Tonight's aurora forecast for West Lake Sammamish
1%
Peak chance of a visible display tonight, from the same model the Revon app runs. West Lake Sammamish 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.
Get the full 30-night forecast in Revon
Updated 2026-09-08 10:36 UTC
Local aurora guide for West Lake Sammamish
West Lake Sammamish generally needs planetary Kp 7 before the aurora borealis reaches the local sky. Historical Kp and darkness data produce about 3.2 viable nights a year across 10.0 years of records.
The strongest historical overlap of darkness and activity occurs in May, September and August.
The central sky is approximately Bortle 6. The supplied darker-sky reference is 28 km east-south-east at Bortle 4.
Aurorasaurus recorded 60 verified reports within 300 km of West Lake Sammamish between 2015-01-01 and 2016-12-31. These records describe past observations, not tonight's prediction.
Sources: Revon analysis of NOAA planetary Kp · Solar declination and hour-angle calculation · Falchi 2016 World Atlas of artificial night sky brightness · Aurorasaurus verified positive reports
Know when it is worth going outside
Revon watches the West Lake Sammamish forecast and pushes an alert when the odds for tonight clear your threshold — no checking, no guessing.
Nearby towns
Forecasts for places within reach of West Lake Sammamish.