IonoFlux field guide
Kp index
How to use the Kp index when checking HF and amateur-radio conditions.
In simple terms
Kp describes how disturbed Earth's magnetic field has been during the last three-hour interval. Kp 0–2 is generally quiet; Kp 5 or more indicates a geomagnetic storm.
How to read it
A high Kp can improve some high-latitude paths while making mid-latitude and low-latitude paths unpredictable. Watch the trend and your actual path, not only one number.
A practical example
If Kp jumps from 2 to 6, the polar route may fade while a lower-latitude route remains usable. The dashboard's live reports help show what is really happening.