# 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 1970 26 25 4 11 13 22 6 7 19K 23 2 16* 30* 17* 9* Feb 1970 7 22 21 8 11 9 12 20 6 25 2 28* 4* 24* 14* Mar 1970 24 22 21 25 16 11 14 23 20 26 8 31 9 7 6 Apr 1970 14 13 10 28 15 1K 2 12 29A 11A 21 22 17 6 20 May 1970 10 26 9 11 8 18 31 16 6 7 28 12* 27* 20* 29* Jun 1970 6 23 22 12 11 30 9 10 25 24 27 18 1 21* 20* Jul 1970 28 7 18 19 15 20K 16 30A 17A 23A 25 9 29 10 21 Aug 1970 5 4 24 3 1 20 14 21 30 2 17 18 8 9* 26* Sep 1970 11 29 12 9 6 7 23 10K 26 28A 13 21 1 14* 27* Oct 1970 21 9 8 7 15 31 26 27 6 20A 18 17 16 4 23 Nov 1970 30 29 1 20 15 2 16 4A 17K 14A 7 21 23 11 22* Dec 1970 1 11 31 10 17 12 16 18 21 26 14 8* 28* 15* 24* Jan 1971 8 7 9 26 12 6 10K 13 1K 17 28 27 3 20 30 Feb 1971 5 13 4 22 3 11 6 28K 7 12 25 15 26 16 14* Mar 1971 29 28 22 21 23 7 6 2 1 5 13 14 31 15 12 Apr 1971 25 24 20 26 8 7K 2A 27A 19A 17A 15 9 14 10 4 May 1971 27 31 12 28 13 11 22 16K 21 20K 17 6 18 7 30* Jun 1971 19 9 7 12 20 27 10 21 24 15 25 2 3 29 1 Jul 1971 10 7 25 20 17 24K 11 16 28K 9K 21 26* 2* 1* 31* Aug 1971 6 27 14 20 3 19 7 15 1 28K 31 2* 11* 18* 23* Sep 1971 2 23 22 21 3 11 10 29 24K 9A 18 27 25 30 7 Oct 1971 19 18 26 17 27 20 16 21 31 23 9 29 8 2 1 Nov 1971 17 16 14 15 3 6 13 2 9 5 23 25 24 22 26* Dec 1971 7 14 6 8 10 15 28 20 5 27 17 18 22* 30* 29* Jan 1972 6 14 13 7 8 9 12 5 3K 31A 23 16 22 28 26 Feb 1972 29 9 12 22 27 28 26K 6 5 23 24 17 13 25* 14* Mar 1972 12 10 14 19 21 20 5 15 13A 11A 7 30 29 24 16 Apr 1972 25 26 3 24 9K 10 16 11K 17 8K 29 28 18 21* 4* May 1972 7 19 21 8 20 24 25 22 4 5K 28 15 2* 1* 16* Jun 1972 30 12 11 10 9 13 21 1 8 25 18 17 19* 27* 4* Jul 1972 5 21 14 13 29 6 4 30 28 1 25 24* 26* 7* 23* Aug 1972 23 24 3 13 2 25K 16 31A 17 30K 5 4 6 9 27 Sep 1972 21 20 5 22 1 7 3 12 4 19K 14 13 17 29 15 Oct 1972 5 17 6 3 8K 9 2 25 10 4A 19 14 13 29 31 Nov 1972 5 13 14 10 30 24 12K 4 8A 9A 1 2 16 20 15* Dec 1972 5 21 10 27 6 11 9 4 25 20 16 13 15 23 30* Jan 1973 2 18 3 22 17 31 7A 16A 14A 15A 27 28 10 20 12 Feb 1973 13 14A 4A 15A 11A 20A 12A 5A 16A 19A 24 23 27 22 21 Mar 1973 15 14 4 17 13 5K 8A 7A 10A 11A 20 19 21 22 25 Apr 1973 12 10 7 6 5A 9A 8A 15A 4A 25A 1 16 29 17 2 May 1973 30 29 24 31 25 5 11K 10A 12A 4A 14 21 15 16 17 Jun 1973 22 1 7 26 27 8 21 25 6A 9A 29 19 11 24 18 Jul 1973 7 6 5 4 21 10K 18 22K 24 17K 26 15 27 31 1* Aug 1973 17 16 11 15 18 10 12K 9 21 19 24 25 28 27 23 Sep 1973 19 30 14 29 28 1 2 3K 18A 12A 23 9 24 25 10 Oct 1973 26 27 25 1 15K 7K 23 8 14A 24A 29 3 21 2 30 Nov 1973 12 19 3 1 30 29 20 11 22A 28 25 7 21 24 18* Dec 1973 2 18 25 16 1 26 12 24 13 3 21 20 4 22 9 Jan 1974 7 23 12 22 24K 13 11 9A 14A 19A 25 26 27 18 29 Feb 1974 18 19 9 15 8 4A 6A 16A 5A 3A 23 12 25 11 26 Mar 1974 18 19 15 17A 4A 13A 7A 12A 14A 8A 21 23 22 16 24 Apr 1974 12 15 16 14 17 13A 8A 2A 30A 1A 18 20 3 19 21 May 1974 10 13 12K 11 6 29A 1A 14A 28A 9A 24 17 5 4 31 Jun 1974 7 8 5 6K 9A 23A 21A 24A 22A 25A 27 26 15 11 12 Jul 1974 18 31 19 22A 30A 17A 21A 3A 16A 1A 6 23 5 24 8 Aug 1974 15 14 12 13 1 17 16 26A 11A 18A 20 21 19 22 23 Sep 1974 17 11 9 12K 10 8A 14A 7A 6A 28A 16 15 21 26 20 Oct 1974 23 7 11K 31A 4A 5A 8A 10A 21A 30A 13 16 15 17 18 Nov 1974 30 29 4 5 2K 3K 28K 1K 7A 18A 12 11 9 13 14 Dec 1974 6 1K 30K 5A 16A 7A 4A 29A 25A 26A 9 18 19 27 13 Jan 1975 2 11 12 26K 25K 10K 29 21 30A 22A 8 7 14 4 13 Feb 1975 27 22A 8A 20A 6A 26A 21A 4A 19A 9A 10 1 11 12 23 Mar 1975 8 7 21 22K 25A 9A 4A 30A 2A 19A 10 11 28 12 27 Apr 1975 29 28 27 17 19 2 30 16 18K 3K 9 10 11 8 13 May 1975 11 15 12 31 28 24 1 30 13K 18A 5 6 16 7 20 Jun 1975 24 10 27 8 23 28 25 26 9 22 2 12 29 30 1 Jul 1975 29 5 30 31K 12 24 23K 6K 21 22 8 25 9 26* 11* Aug 1975 12 19 3 13 26 28 7 16 18 27K 5 29 15* 21* 14* Sep 1975 24 4 25 30 3 22 5 23 29 16 10 11 9 12* 13* Oct 1975 2 25 19 24 15 18 20 27K 26 22 8 9 7 6 10 Nov 1975 14 13 27 15K 16 18A 8A 1A 23A 19A 3 22 4 9 2 Dec 1975 12 13 24 7 20 11 19 14 18 31A 26 27 1 2 8* Jan 1976 9 2 1 28 26 8 29 27K 15A 19A 11 10 31 22 24 Feb 1976 24 25 23 16 15A 6A 5A 26A 4A 11A 29 8 27 19 9 Mar 1976 22 24 25 23 21 20A 31A 19A 30A 13A 26 8 9 27 10 Apr 1976 20 18 15 19 21 26 17 23A 16A 25A 1 3 4 6 5 May 1976 18 17 14 16 9 27 15K 26 13 24 3 2 4 29 20* Jun 1976 14 22 21 9 19 23 15K 13 16 29 11 30 18 4 5 Jul 1976 21 20 11 13 26 22 24 23 17 12 30* 29* 1* 15* 16* Aug 1976 15 13 12 18 8 14 4 17 6 11 23 25 24 26* 27* Sep 1976 11 13 10 28 9 16 24A 6A 8A 12A 20 18 25 21 2 Oct 1976 29 26 28 25 22 24K 7 8 4 9 31 15 17 16 2 Nov 1976 28 6 5 24 23 21 7 4 18 22 13 12 11 10* 14* Dec 1976 15 2 6 3 14 21 20 23 28 5 29 18 8 9* 12* Jan 1977 10 26 27 2K 21 23 9 17 8 13A 30 14* 31* 1* 29* Feb 1977 27 4 20 16K 19 21A 1A 26A 22A 12A 9 2 7* 8* 18* Mar 1977 4 5 31 3 2 15 7 19 30 16 9 12 11* 10* 26* Apr 1977 27 26 1 28 2 23 13 22 30A 18A 19 7 6 8 20 May 1977 29 26 8 27 21 19 30 25 7 13K 2 11 16 17* 12* Jun 1977 15 11 12 25 6 4 8 9 26 3 2* 28* 20* 23* 18* Jul 1977 26 27 28 12 25 5 23 24A 18A 31A 29 20 16 6 19 Aug 1977 31 2 21 30 22 29 1 23 3A 28A 5 17 11 25 19 Sep 1977 5 6 29 1 30 2 7K 12K 4K 18K 22 21 20 19 13 Oct 1977 9 7 1 25 10 2 21 31 26K 24 27 28 12 19 22 Nov 1977 24 23 9 8 22 3 20 1 21K 28 14 15 13 26* 12* Dec 1977 8 18 19 7 20 9 23 10 15 6 2 11 12 5* 13* Jan 1978 21 23 15 22 14 20 12 27 24K 19 4 29 30 6 5 Feb 1978 24 11 23 7A 10A 13A 17A 12A 8A 4A 28 27 15 26 22 Mar 1978 4 12 25 24K 5 11A 6A 21A 31A 7A 27 26 1 2 17 Apr 1978 8 7 9 29 17A 16A 22A 21A 6A 1A 11 14 30 4 24 May 1978 19 27 18 6 15 28A 16A 26A 7A 5A 2 4 9 3 1 Jun 1978 9 14 16 15 13A 6A 1A 12A 8A 17A 2 26 5 21 30 Jul 1978 31 30 29 27 12 20 2 26 17 11 4 14 5 13 18* Aug 1978 20 26 15 1 23 2 24 9 16 22 28 31 29 30 4 Sep 1978 19 18 15 14K 20K 16 7K 13 5A 17A 29 28 27 26 25 Oct 1978 6 16 7 15 14 17 24 8 11 23 18 30 27 19 31 Nov 1978 6 28 29 30 18 4 17 5K 16 7A 25 12 26 22 20 Dec 1978 10 11 7 9 2 8 12 3 6 24 18 30 15 20 14 Jan 1979 10 11 13K 17A 14A 8A 1A 12A 21A 18A 4 25 26 7 23 Feb 1979 13 14 17 20 10 7 1 16A 8A 3A 21 22 23 27 26 Mar 1979 14 21 20 12 7A 8A 18A 13A 15A 16A 29 10 28 22 6 Apr 1979 20 19 11K 18 17A 9A 26A 10A 13A 7A 25 5 29 22 4 May 1979 17 16 6 31 3 10A 4A 5A 8A 13A 22 25 24 26 19 Jun 1979 5 3 28 1 18 2 4 19 12A 29A 7 6 22 23* 16* Jul 1979 31 25 2 11 24 22 10 23 9K 1A 7 29 6 27 20* Aug 1979 15 23 16 9 10A 17A 14A 5A 8A 11A 29 13 20 19 21 Sep 1979 9 2 7K 8 19K 22 23A 13A 12A 15A 18 21 20 26* 25* Oct 1979 18 17 19 30 27 31 5 14 23 20 8 6 7 9 10* Nov 1979 28 5 22 6 15 23 26 29 18 27 13 24 9* 8* 1* Dec 1979 25 13 23 7 12 14 21 20 11 10 29 30 4* 28* 22*