Geomagnetic K-index of 4 – Alert issued on June 13, 2026

A Geomagnetic K-index of 4 Alert was issued by NOAA SWPC on June 13, 2026, at 21:01 UTC. The alert indicates that the K-index reached a threshold of 4 during the synoptic period from 18:00 to 21:00 UTC. This is considered an active geomagnetic condition, with the alert currently marked as active by the Space Weather Prediction Center.

The primary area of impact is expected to be poleward of 65 degrees geomagnetic latitude. Weak power grid fluctuations are possible due to induced currents, and auroral displays may be visible at high latitudes, such as in Canada and Alaska. This level of geomagnetic activity generally does not cause severe disruptions to infrastructure but can be noticeable in sensitive high-latitude regions.

According to the latest SWPC forecast discussion, today’s enhanced geomagnetic conditions are associated with continued negative polarity coronal hole high-speed stream (CH HSS) influences and the passage of coronal mass ejections (CMEs) that left the Sun on June 9 and 11. Solar wind speeds increased following these influences, supporting the heightened geomagnetic activity observed during the period.