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

Tomorrow

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

Day After Tomorrow

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

27 Day Aurora Forecast

Oct 25
2
Oct 26
2
Oct 27
3
Oct 28
3
Oct 29
3
Oct 30
3
Oct 31
2
Nov 01
2
Nov 02
2
Nov 03
2
Nov 04
2
Nov 05
2
Nov 06
4
Nov 07
3
Nov 08
3
Nov 09
2
Nov 10
2
Nov 11
2
Nov 12
2
Nov 13
2
Nov 14
2
Nov 15
3
Nov 16
3
Nov 17
2
Nov 18
2
Nov 19
2
Nov 20
2