# 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. Quietest Days Most Disturbed Days Month Q1 Q2 Q3 Q4 Q5 Q6 Q7 Q8 Q9 Q10 D1 D2 D3 D4 D5 Jan 1950 8 31 17 29 3 23 18K 12 5 2A 24 25 20 14 21* Feb 1950 26 17 10 13 18 16 27 11 19 14 21 20 23 24 22 Mar 1950 11 10 13 18 12 8 4 23 5 17 19 27 21 22 24 Apr 1950 21 26 27K 14 22K 11A 8A 25A 9A 10A 5 1 2 30 24 May 1950 9 18 8 19K 12 17 31K 1 21A 20A 28 3 27 23 15 Jun 1950 13 15 19 28 20 7 27 14 16K 4A 24 30 6 29 9 Jul 1950 23 19 26 18 2 8 20 17A 27A 10A 12 25 24 11 4 Aug 1950 26 17 25 24 16 27 5 22 23A 31A 19 20 8 10 9 Sep 1950 29 15 14 22 1 2 28A 21A 12A 27A 5 3 6 4 8 Oct 1950 27 21 19 10 11 25K 20 26 24A 22A 28 2 29 1 31 Nov 1950 7 20 15 6 21K 19K 9 16 8A 23A 26 1 25 27 4 Dec 1950 11 31 4 1K 21K 17A 29A 30A 3A 5A 24 13 23 14 25 Jan 1951 7 6 9 18 4A 25A 8A 20A 5A 17A 22 31 23 28 15 Feb 1951 16 3 17 15 2 20 7A 4A 21A 19A 23 28 27 22 24 Mar 1951 28 5 2A 21A 4A 31A 20A 30A 19A 3A 13 22 14 8 10 Apr 1951 30 1A 16A 28A 15A 27A 17A 11A 29A 26A 3 5 18 6 4 May 1951 21 8 13 20 28 22A 7A 5A 19A 31A 2 1 10 26 3 Jun 1951 23K 10A 24A 20A 4A 22A 5A 30A 3A 29A 18 25 19 15 17 Jul 1951 14 12A 13A 24A 21A 11A 10A 7A 8A 6A 2 31 28 22 26 Aug 1951 18K 8A 3A 30A 10A 14A 6A 7A 9A 19A 21 20 13 25 26 Sep 1951 2 1A 4A 7A 3A 8A 30A 28A 5A 9A 25 20 21 22 16 Oct 1951 25 6 31 4 24 5K 1A 3A 30A 27A 17 28 8 19 18 Nov 1951 10 1 19A 27A 11A 18A 8A 21A 26A 16A 14 13 3 4 15 Dec 1951 26 24 25 6K 21A 30A 13A 29A 14A 16A 28 8 9 31 22 Jan 1952 18 20 19 26K 21 17A 2A 22A 3A 31A 5 13 14 15 12 Feb 1952 5 4 21 22K 3 15A 23A 17A 20A 2A 24 16 8 6 27 Mar 1952 20 28 2 19A 29A 14A 13A 18A 1A 26A 5 31 6 4 7 Apr 1952 27 26A 20A 25A 12A 11A 14A 24A 17A 18A 29 3 2 21 30 May 1952 16 9 22 15 17K 10K 23A 14A 12A 13A 27 7 3 2 1 Jun 1952 7 21 20 13 6 4K 19 28A 2A 12A 30 24 9 23 14 Jul 1952 29 30 28 19 2A 18A 17A 12A 27A 7A 5 21 20 6 9 Aug 1952 25 14 28 16K 26 22 24 21 13 15K 18 17 3 30 12 Sep 1952 19 23 18 13 17 22A 16A 20A 4A 24A 29 8 1 30 9 Oct 1952 24 23 22 15 13A 20A 16A 19A 14A 27A 4 5 31 26 30 Nov 1952 13 10 12 11 4 19 20 5 14 18A 27 21 1 26 28 Dec 1952 9 23 21 20 19 8 14 7 22A 6A 4 29 13 30 2 Jan 1953 16 15 17 10 4 12 23A 22A 7A 11A 5 26 27 28 19 Feb 1953 7 13 6 5 1 8 12 18 20K 3 24 26 25 23 22 Mar 1953 18 13K 12 17 11A 31A 6A 5A 4A 20A 2 24 25 9 23 Apr 1953 7 14 5 28A 6A 9A 8A 24A 29A 27A 16 20 4 21 23 May 1953 13 14 3 2 12 30 1 25 29 4 16 15 6 8 19 Jun 1953 26 23 27 16 19 28 1 9 8 25 2 29 30 3 4 Jul 1953 16 17 18 11K 21 19 22K 10K 20A 25A 27 23 29 2 1 Aug 1953 20 21 22 19 17 18 5 6 8 3A 24 30 27 12 23 Sep 1953 14 29 9A 30A 28A 10A 26A 13A 8A 12A 19 4 23 3 20 Oct 1953 14 5 12 13 6 4 26 2 3A 30A 19 18 16 15 20 Nov 1953 10 28 30 2 9 8 4 1 11 7 13 15 19 14 16 Dec 1953 1 2 31 30 23 21 10 26 3 16 11 12 13* 22* 4* Jan 1954 4 29 28 26 10 27 24 1 30 14 19 2 20* 21* 23* Feb 1954 6 7 12 5 8 13A 20A 9A 10A 14A 22 26 27 15 21 Mar 1954 29 28 1A 3A 27A 10A 6A 4A 31A 8A 23 14 15 24 22 Apr 1954 28 29A 1A 7A 25A 17A 22A 16A 6A 5A 12 11 20* 15* 4* May 1954 17 7 30 25 1 22 27K 28 26 16K 11* 4* 18* 9* 21* Jun 1954 5 8 16 24 11 15 17 6 29 1 10* 28* 12* 13* 14* Jul 1954 4 9 3 10 2 11 22 5 13 8 28* 25* 14* 27* 1* Aug 1954 3 8 5 13 4K 12A 20A 10A 15A 11A 24 6* 26* 22* 29* Sep 1954 12 23A 8A 13A 19A 24A 17A 10A 26A 22A 20 29 14 1 21 Oct 1954 12 13 10 9K 15 29K 21 11K 14K 28 24 1 18 3 25 Nov 1954 16 15 10 17 9 13 7 8 11 28 1 2 3* 30* 20* Dec 1954 15 11 16 10 14 24 26 23 22 6 27* 17* 18* 20* 7* Jan 1955 15 26 25 10 24 3 31 8 22 5K 18 19 17 9 20* Feb 1955 1 2 27 19 10 16 17K 15A 20A 18A 28 23 4* 22* 5* Mar 1955 1 29 2 3 4 28 19 25 20K 21A 31 22 7 9 10 Apr 1955 18 23 19 16 15 17 9K 21A 14A 22A 28 27 29 5* 7* May 1955 23 19 24 21 17 18 30 22 11 2 26 8 6 25 7 Jun 1955 30 26 21 5 10 3 20K 27 29 11K 8 15* 23* 24* 16* Jul 1955 19 4 5 28 20 21 22 1 25 14 12 11* 2* 26* 15* Aug 1955 22 23 11 1 25 12 2 20 21 30 6 4 5* 28 7* Sep 1955 26 25 21 11 15 10 14K 9A 24A 8A 30 5 13 27 29 Oct 1955 12 18 24 13 19 15 17 21 14 23 25 26 31 5 6 Nov 1955 7 6 3 22 23 10 14 26 30 27 19 20 18 16 4 Dec 1955 29 14 18 23 13 30 17 11 12 15 1 25* 26* 27* 6* Jan 1956 26 15 20 8 16K 17A 13A 14A 21A 7A 18 11 28 24 19 Feb 1956 8 9 10 7 14 18 15 17 20K 5 25 29 12 28 11 Mar 1956 9 8 17 7 18 16 15A 5A 12A 13A 3 22 29 21 24 Apr 1956 24 15A 14A 13A 25A 20A 9A 23A 8A 12A 27 22 28 21 30 May 1956 10 9 8 2 11K 31 27A 19A 7A 18A 16 24 25 17 15 Jun 1956 18A 7A 20A 19A 3A 22A 4A 17A 12A 21A 25 24 15 30 1 Jul 1956 7 21 18 22 17 6 4A 15A 16A 5A 26 25 24 28 13 Aug 1956 19 20 7 18 5 4 15 6 14 16 24 25 26 11 23 Sep 1956 18 19 14 29 17 15K 27 24 30A 5A 2 8 3 22 21 Oct 1956 15 14 13 25 17 18 16 12 19 10 20 26 21 27 2 Nov 1956 19 5 8 26K 7A 2A 4A 24A 27A 6A 15 11 14 10 16 Dec 1956 16 17 15 11 21 23 19 31 20 9 10 28 25 13* 30* Jan 1957 18 14 20 5 13 4 17 6 28A 12A 21 22 30 10 23 Feb 1957 28 26 7 10K 27K 1A 9A 8A 14A 16A 24 13 5 21 4 Mar 1957 14 12A 11A 7A 13A 19A 24A 15A 26A 20A 2 29 10 28 27 Apr 1957 7 14 22 25A 13A 23A 8A 12A 30A 29A 19 10 17 18 5 May 1957 16 15 29 12 24K 14 18 22 28 17A 26 30 9 1* 20* Jun 1957 11 10 9 1 2 29 16 12A 14A 8A 30 26 25 4 3 Jul 1957 13 26 10 15 11 30 14 21 9 28K 1 5 2 3 19 Aug 1957 24 23 17 22 11 16 1 25A 18A 14A 30 13 31 6 3 Sep 1957 27 19 11 20 8A 12A 10A 26A 28A 7A 23 13 3 29 4 Oct 1957 6 8 16 7 18 17A 9A 31A 26A 25A 14 21 13 1 11* Nov 1957 5 4 21 22 17K 23A 2A 1A 19A 30A 26 27 25 9 28 Dec 1957 23 28 22 29K 27 24A 14A 4A 8A 18A 31 11 12 6 1 Jan 1958 4 3 8 7 5K 6A 28A 27A 30A 31A 1 21 18 17 23 Feb 1958 25 3K 26A 15A 24A 2A 1A 27A 16A 28A 11 12 18 17 6 Mar 1958 1K 2A 29A 28A 16A 27A 14A 10A 31A 9A 12 13 19 5 20 Apr 1958 10 13 12 22 11A 23A 9A 8A 27A 25A 17 18 4 2 16 May 1958 24 23 20 22 7 21K 3A 6A 4A 25A 31 29 26 14 13 Jun 1958 17 4 3 18A 20A 27A 26A 5A 19A 30A 29 7 21 1 28 Jul 1958 15 6 23 2 16A 29A 28A 26A 5A 30A 8 9 21 18 27 Aug 1958 4 6 8 5 20 21 9A 14A 31A 15A 24 17 27 22 18 Sep 1958 13 22 21 18 14 20 19 2 23 12 4 25 5 3 16 Oct 1958 12 10 9 4 11 20K 21K 14A 13A 18A 24 23 22 27 28 Nov 1958 30 5 6 8 22 14 21 20 9 19 11* 28* 2* 10* 3* Dec 1958 1 10 25 7 12 31A 3A 24A 21A 11A 4 18 13 17 19 Jan 1959 1 21 2 20 24 3 4A 22A 14A 23A 9 10 6 5 18* Feb 1959 24 20 18 10 21 7A 1A 8A 19A 23A 25 16 26 28 4 Mar 1959 10 9 16 11 22 20 17 21 6K 19 27 28 26 29 1 Apr 1959 22 20 19 18 5 6 16 2 4A 17A 10 9 23 24 29 May 1959 29 6 28 27 14 7K 30K 3A 2A 26A 12 24 8 16 15 Jun 1959 13 17K 12K 16 25K 1A 19A 21A 20A 15A 29 30 28 27 4 Jul 1959 30 3 1 29A 13A 6A 10A 23A 4A 2A 15 18 17 16 25 Aug 1959 28 27 12 13 14 26A 11A 5A 30A 31A 16 17 20 21 18 Sep 1959 9 7A 10A 29A 8A 30A 13A 12A 11A 16A 4 21 22 20 25 Oct 1959 11 13 16 28 10 21K 29K 9K 24 12A 4 6 1 3 31 Nov 1959 15 20K 11 12A 24A 16A 9A 25A 10A 7A 28 2 1 3 30 Dec 1959 21 10 11 22K 7K 20 31A 8A 17A 9A 5 3 28 14 27