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
1
03-06h
0
06-09h
1
09-12h
1
12-15h
2
15-18h
2
18-21h
2
21-00h
2

Tomorrow

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

Day After Tomorrow

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

27 Day Aurora Forecast

Feb 17
3
Feb 18
3
Feb 19
3
Feb 20
3
Feb 21
2
Feb 22
3
Feb 23
3
Feb 24
2
Feb 25
3
Feb 26
4
Feb 27
3
Feb 28
2
Feb 29
2
Mar 01
2
Mar 02
2
Mar 03
2
Mar 04
5
Mar 05
4
Mar 06
3
Mar 07
2
Mar 08
2
Mar 09
2
Mar 10
2
Mar 11
2
Mar 12
2
Mar 13
2
Mar 14
2