Indices of Global Geomagnetic Activity

This service contributes to the International Service of Geomagnetic Indices (ISGI) of the IAGA.

The planetary three-hour-range Kp index was introduced by J. Bartels in 1949 and is derived from the standardized K index (Ks) of 13 magnetic observatories. It is designed to measure solar particle radiation by its magnetic effects.

The geomagnetic ap, Ap, Cp and C9 and the classification of international Q-days and D-days are derived from the Kp index.

Quicklook Kp Index

Quicklook Kp index, shown daily in a bar plot with an overview of the last six days.

Most Recent Definitive Indices

Planetary magnetic three-hour-range indices, shown in old style musical diagram.

Kp index data from this website is distributed under the Creative Commons Attribution 4.0 International (CC BY 4.0)


Profile photo of  Dr. Jürgen Matzka

Dr. Jürgen Matzka

Lindenstr. 7
Building H 1, room 213
14823 Niemegk
tel. +49 33843 624-18


Profile photo of  Prof. Dr. Claudia Stolle

Prof. Dr. Claudia Stolle

Behlertstraße 3a
Building K 3, room 006
14467 Potsdam
tel. +49 331 288-1230

In cooperation with:

International Association of Geomagnetism and Aeronomy
Service International des Indices Geomagnetiques