# 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 1936 6 7 4 3 2 16 5 17 1K 20K 26 25 18* 24* 13* Feb 1936 13 28 6 7 12 8 1 5 18 29K 17 16 19 22 21 Mar 1936 3 11 4 12 7 2 13 14 1 30 24 21 23 25* 20* Apr 1936 5 29 6 10 27 26 9 7 30A 28A 21 22 18 19 23 May 1936 24 9 6 8 23 7 3 25 2 5 18 12 19 16 4 Jun 1936 6 23 30 29 28 5 21 25 7 27K 19 9 2 15 10* Jul 1936 23 21 24 1 22 14 26 4 15 27 2 11 6 29 10 Aug 1936 23 7 18 11 24 19 17 16 22 14 30* 10* 8* 6* 1* Sep 1936 16 7 13 19 25 3 20 30 1 14 26* 11* 29* 23* 9* Oct 1936 27 22 2 4 12 3 28 13 30 26 17 31 10 16 24* Nov 1936 13 25 23 24 27 22 1 14 21 2K 29 3 11 18* 15* Dec 1936 19 26 25 24 22 10 9 17 16 15 28 27* 4* 5* 1*