Current Kp Index

What is the Kp Index?

The Kp index is a 0-9 scale that measures global geomagnetic activity, based on real-time magnetometer readings and updated every minute by NOAA's Space Weather Prediction Center. Higher numbers mean a stronger geomagnetic storm and a better chance of seeing the aurora at lower latitudes - a Kp of 3 or higher often pushes visible aurora into the northern Lower 48, and a Kp of 6 or higher can bring it as far south as the Midwest.

Bz is the north-south direction of the interplanetary magnetic field. A negative (southward) Bz connects more efficiently with Earth's own field and tends to drive stronger aurora, even when Kp hasn't caught up yet.

For a full forecast that combines Kp, Bz, cloud cover, and sky darkness for your location, see the Northern Lights Prediction.