Northern Lights Forecast for August 31, 2025

Lead: Geomagnetic activity remains at moderate levels today, with a Kp index of 3 expected through August 31. Forecasters warn of an incoming solar storm that could spark visible auroras across much of North America and Europe on the nights of September 1-2.

Today’s Conditions According to the Geophysical Institute at the University of Alaska, the predicted Kp index for August 31 is 3, indicating unsettled geomagnetic activity that may produce faint auroras in high-latitude locations under dark skies.

Upcoming Geomagnetic Storm Watch NOAA’s Space Weather Prediction Center has issued a G1 (minor) geomagnetic storm watch effective from September 1 into September 2. This watch follows a coronal mass ejection (CME) from sunspot AR 4199 that erupted on August 30. When the CME impacts Earth’s magnetic field, storm levels are expected to reach G2 (moderate) and possibly G3 (strong), extending auroral visibility to much lower latitudes than usual.

Expected Visibility

  • In Canada and the northern U.S., including states as far south as Pennsylvania, Indiana, Nebraska, and Oregon, skywatchers may see green or red northern lights after local midnight on September 1.
  • Mid-latitude observers could catch a diffuse green glow on the northern horizon, especially in rural areas away from city lights.
  • High-latitude regions (e.g., Alaska, Scandinavia, Scotland) stand the best chance of bright, overhead displays.

Viewing Tips

  1. Choose a dark site with an unobstructed view of the northern horizon.
  2. Allow 20-30 minutes for eyes to adjust to darkness.
  3. Set up long-exposure photography using a tripod to capture faint auroral features.
  4. Monitor live Kp and Bz data via NOAA’s Ovation map for real-time confirmation of storm arrival.

Outlook Short summer nights have limited aurora watching opportunities until early September. With nights now lengthening, the coming geomagnetic storm could offer one of the best aurora displays of the season. Skywatchers should prepare for peak activity late on September 1 (UTC), which corresponds to the early hours of Labor Day in North America.

Stay tuned to space weather updates and local sky conditions for the latest on this developing aurora event.