The K-index quantifies disturbances in the horizontal component of earth’s magnetic field with an integer in the range 0–9 with 1 being calm and 5 or more indicating a geomagnetic storm. It is derived from the maximum fluctuations of horizontal components observed on a magnetometer during a three-hour interval.

The official planetary Kp-index is derived by calculating a weighted average of K-indices from a network of geomagnetic observatories. Since these observatories do not report their data in real-time, various operations centers around the globe estimate the index based on data available from their local network of observatories. The Kp-index was introduced by Bartels in 1939.

Today

00-03h
4
03-06h
3
06-09h
1
09-12h
1
12-15h
1
15-18h
2
18-21h
2
21-00h
2

Tomorrow

00-03h
2
Clear sky
03-06h
2
Clear sky
06-09h
1
Clear sky
09-12h
1
Clear sky
12-15h
1
Clear sky
15-18h
2
Clear sky
18-21h
3
Clear sky
21-00h
4
Clear sky

Day After Tomorrow

00-03h
5
Clear sky
03-06h
4
Clear sky
06-09h
4
Clear sky
09-12h
3
Clear sky
12-15h
3
Clear sky
15-18h
2
Clear sky
18-21h
2
Clear sky
21-00h
3
Clear sky

27 Day Aurora Forecast

Mar 01
5
Mar 02
4
Mar 03
3
Mar 04
2
Mar 05
2
Mar 06
4
Mar 07
2
Mar 08
2
Mar 09
2
Mar 10
2
Mar 11
2
Mar 12
4
Mar 13
4
Mar 14
2
Mar 15
4
Mar 16
3
Mar 17
2
Mar 18
5
Mar 19
5
Mar 20
4
Mar 21
4
Mar 22
3
Mar 23
3
Mar 24
2
Mar 25
2
Mar 26
2
Mar 27
2