# DOI: https://doi.org/10.5880/Kp.0001 # LICENCE: CC BY 4.0, please cite: # Matzka, J., Bronkalla, O., Tornow, K., Elger, K. and Stolle, C., 2021. # Geomagnetic Kp index. V. 1.0. GFZ Data Services, # https://doi.org/10.5880/Kp.0001 # Matzka, J., Stolle, C., Yamazaki, Y., Bronkalla, O. and Morschhauser, A., # 2021. The geomagnetic Kp index and derived indices of geomagnetic activity. # Space Weather, https://doi.org/10.1029/2020SW002641 # The Kp index was introduced by Bartels (1949) and is produced by Geomagnetic # Observatory Niemegk, GFZ German Research Centre for Geosciences. International Quietest Days Most Disturbed Days Month Q1 Q2 Q3 Q4 Q5 Q6 Q7 Q8 Q9 Q10 D1 D2 D3 D4 D5 Jan 1944 3 30 7 8 25 6 24K 29 4 9 13 11 14 12 15 Feb 1944 3 27 26 25 19 18 6 24 23 1 14 7 8 15 10 Mar 1944 17 24 3 1 15K 21A 20A 23A 16A 25A 27 26 10 19 7 Apr 1944 23 13 22 14 19 20 21 18K 25A 12A 2 16 6 10 5 May 1944 20 16 13 21 18 19 14 17 22 10 1 2 29 6 4 Jun 1944 8 12 3 7 25 6 10 13 19 2 22 15* 26* 21* 23* Jul 1944 24 25 26 27 12 8 28 29 23 11 9* 20* 15* 21* 19* Aug 1944 25 21 29 26 20 22 7 17 16 15 3 28 18 2* 31* Sep 1944 19 17 15 16 6 9 7K 28 13K 10A 30 2 24 21* 23* Oct 1944 8 19 29 9 21 5 30 22 20K 10K 15 11 14 1 3* Nov 1944 13 25 24 27 17 14 21 22 28 15 5 20 6* 4* 10* Dec 1944 7 24 25 12 11 8 10 23 9K 4K 16 17 27 18* 30*