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.

EXTENDED NORTHERN LIGHTS FORECAST

Today

00-03h

2

03-06h

3

06-09h

3

09-12h

3.33

12-15h

4

15-18h

3.33

18-21h

4

21-00h

3

Tomorrow

00-03h

3

03-06h

2

06-09h

2

09-12h

2

12-15h

2

15-18h

2

18-21h

2

21-00h

2.33

Day After Tomorrow

00-03h

1.67

03-06h

1.33

06-09h

1.33

09-12h

1.33

12-15h

1.33

15-18h

1.33

18-21h

1.67

21-00h

1.67

27 Day Aurora Forecast

Oct 19

5

Oct 20

5

Oct 21

4

Oct 22

3

Oct 23

2

Oct 24

4

Oct 25

3

Oct 26

2

Oct 27

2

Oct 28

2

Oct 29

2

Oct 30

2

Oct 31

5

Nov 01

5

Nov 02

3

Nov 03

2

Nov 04

2

Nov 05

3

Nov 06

3

Nov 07

3

Nov 08

2

Nov 09

4

Nov 10

3

Nov 11

3

Nov 12

3

Nov 13

2

Nov 14

2