First published 10/4/2026, 11:21:15 AM · Last updated 10/4/2026, 11:21:15 AM

Warning: Geomagnetic K-index of 5 expected

A warning issued October 4, 2026, said a geomagnetic K-index of 5 was expected from 1110 to 2100 UTC. The source described a minor G1 event and possible weak grid fluctuations, minor satellite impacts, and aurora visibility at high latitudes.

Illustrative image: Sun Emits a Solstice CME — NASA/GSFC/NASA Image and Video Library, NASA Media Usage Guidelines

Categories: science-and-space, energy-and-resources

Generated scores

Scores are based on the cited reporting and use a 1–10 scale. Read the methodology.

Confidence: 6/10How certain the assessment is based on the clarity and evidence in the cited reporting.
Geographic reach: 3/10How widely the event reaches, from a local area (1) to worldwide impact (10).
Global importance: 2/10The event's broader significance, from limited importance (1) to major global importance (10).
Impact magnitude: 2/10The scale or severity of the real-world impact, from minor (1) to extreme (10).
Positivity: 4/10How harmful or beneficial the event is, from strongly harmful (1) to strongly positive (10).
Urgency: 3/10How time-sensitive the event is, from low urgency (1) to immediate attention needed (10).

Why it matters

The warning identifies possible effects on power grids, satellite operations, and aurora visibility.

Sources

Warning: Geomagnetic K-index of 5 expectedNOAA/NWS Space Weather Prediction Center Usage terms

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