Space weather / EVENT RECORD

ALERT: Geomagnetic K-index of 4

NOAA SWPC · Every measurement below belongs to the selected record.

Bulletin issued

2026-10-09 10:01:02.860Z

Source update / publication

2026-10-09 10:01:02.860Z

ALERT: Geomagnetic K-index of 4 · Threshold Reached: 2026 Oct 09 1001 UTC · Synoptic Period: 0900-1200 · Active Warning: YES · Comment: · NOAA Space Weather Scale descriptions can be found at · www.swpc.noaa.gov/noaa-scales-explanation

This is a source-linked archive. Source measurements and assessments can change. An archived bulletin is not evidence that a warning is currently active.

In the daily journal

SOURCE ID swpc:K04A:2026-10-09T10:01:02.860Z