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

1.67

03-06h

2

06-09h

1.67

09-12h

1.33

12-15h

1.33

15-18h

0.67

18-21h

0.67

21-00h

1.67

Tomorrow

00-03h

2.67

03-06h

3

06-09h

3.67

09-12h

2.67

12-15h

2.67

15-18h

1.67

18-21h

1.67

21-00h

2.67

Day After Tomorrow

00-03h

2.33

03-06h

1.67

06-09h

2

09-12h

2.33

12-15h

2.33

15-18h

2.33

18-21h

2.33

21-00h

2.33

27 Day Aurora Forecast

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

Nov 15

2

Nov 16

3

Nov 17

5

Nov 18

5

Nov 19

3

Nov 20

2

Nov 21

2

Nov 22

2

Nov 23

2

Nov 24

2

Nov 25

2

Nov 26

3

Nov 27

5

Nov 28

5