MEI Ranks (last update: 14 June 2013) Bimonthly ranks of the MEI, since the beginning of record in Dec1949/Jan1950. If two MEI values are identical within the same bimonthly season, their rank is split between them, leading to a ".5" value. Missing values are left blank. How can one interpret these ranks? Given that there are 63 numbers in each column, the lowest number (1) would denote the strongest La Nina case for that bimonthly season, while the highest number (63) would indicate the strongest El Nino case. For instance, in December-January (DECJAN), the strongest La Nina was recorded in 1974, while the strongest El Nino occurred in 1983. If we use percentiles (say, 30%ile) to define La Nina, near-normal, and El Nino, MEI ranks from 1-19 denote strong to weak La Nina conditions, while 45-63 (46-64) denote weak to strong El Nino conditions. If one uses the quintile definition for (moderate or stronger) ENSO events, MEI ranks from 1-12 would denote La Nina, while 52-63 (53-64) would denote El Nino. Finally, the comparison figures on this website refer to strong ENSO events, such as might be defined by the top 6 (one tenth or smaller) ranks, such as 1-6 for La Nina, and 58-63 (59-64) for El Nino. YEAR DECJAN JANFEB FEBMAR MARAPR APRMAY MAYJUN JUNJUL JULAUG AUGSEP SEPOCT OCTNOV NOVDEC 1950 12 11 6 8 4 5 5 10 18 21 11 7 1951 10 10 8 22 22 42 48 52 50 47 46 43 1952 44 37 36.5 38 23 14 21 28 39 40 25 32 1953 36 43 44 56 56 36 39 37 44 35 35 37 1954 34 36 42 19 3 2 4 5 11 7 12 10 1955 15 19 10 3 1 1 1 1 3 3 1 2 1956 4 7 5 6 5 3 7 9 7 5 15 11 1957 14 27 40 44 57 47 52 57 58 57 55 57 1958 60 59 59 59 53 51 47 41 33 38 41 48 1959 46 51 49 37 29 32 24 32 31 29 27 28 1960 29 30 32 32 19.5 21 19 23 22 24 26 24 1961 33 29 31 31 21 27 25 24 26 19 21 18 1962 9 12 17 9 9 8 13 14 19 18 19 23 1963 17 14 18 15 16 29 41 44 47 48 50 49 1964 52 45 23 17 6 7 3 4 8 9 8 16 1965 24 28 27 34 47 55 58 59 59 58 60 59 1966 59 58 51 52 26 24 27 35 29 31 34 29 1967 26 13 11 7 15 18 14 18 16 17 22 25 1968 19 18 19 11 7 11 15 30 35 41 43 40 1969 48 52 47 54 51 48 40 34 32 43 45 41 1970 43 44 43 27 25 10 10 11 9 11 13 6 1971 5 3 1 1 2 4 6 8 6 6 6 13 1972 20 26 26 23 44 58 62 60 60 61 61 61 1973 61 60 53 49 27 9 11 7 4 4 4 1 1974 1 1 2 2 8 13 12 13 17 12 7 15 1975 21 21 14 12 10 6 2 3 2 1 2 3 1976 3 5 7 5 14 38 45 46 56 50.5 40 44 1977 45 39 38 51 39 44 51 48 53 53 52 50 1978 51 53 56 35 17 15 18 26 24 30 37 42 1979 47 42 33 39 41 39 37 45 49 45 47 53 1980 49 48 50 58 58 49 49 39 38 37 38 35 1981 32 34 46 55 33 30 30 31 34 34 32 31 1982 31 35 36.5 29 42 54 59 61 61 62 62 63 1983 64 64 64 64 64 62 60 58 41 32 29 30 1984 28 24 39 42 34 25 28 27 30 33 24 19 1985 22 22 15 21 11 26 26 21 20 28 33 27 1986 30 32 34 24 38 37 38 51 57 52 51 55 1987 58 57 61 61 61 61 61 62 62 60 57 58 1988 54 49 48 40 32 12 8 6 5 8 5 5 1989 7 6 13 14 13 20 17 15 25 25 31 36 1990 38 47 55 45 49 40 32 33 40 39 39 39 1991 41 40 45 48 52 57 55 56 46 54 56 60 1992 62 62 62 62 62 60 54 42 43 46 44 47 1993 50 56 57 60 60 59 56 55 55 56 49 45 1994 42 38 41 47 46 46 50 49 54 59 58 56 1995 57 55 54 46 45 41 34 25 23 20 20 22 1996 18 23 24 20 24 31 22 20 21 22 30 26 1997 25 20 25 50 59 63 63 63 63 63 63 62 1998 63 63 63 63 63 56 36 19 14 15 10 12 1999 8 9 12 10 12 17 16 12 12 13 14 8 2000 6 8 9 18 35 23 23 29 27 23 17 21 2001 23 16 20 26 37 28 35 40 28 26 28 33 2002 35 31 28 43 55 50 44 53 52 50.5 53 54 2003 56 54 52 41 30 33 33 36 42 44 42 38 2004 40 41 30 36 43 35 42 47 45 42 48 46 2005 39 50 58 53 54 43 43 38 36 27 23 20 2006 27 25 21 16 28 45 46 50 51 49 59 51 2007 53 46 35 28 36 19 20 17 10 10 9 9 2008 13 4 3 13 18 34 31 22 15 16 18 17 2009 16 15 16 25 40 53 53 54 48 55 54 52 2010 55 61 60 57 48 16 9 2 1 2 3 4 2011 2 2 4 4 19.5 22 29 16 13 14 16 14 2012 11 17 22 33 50 52 57 43 37 36 36 34 2013 37 33 29 30 31 Next update: 9 July 2013 (or earlier) Link to numerical MEI values is here. Go back to MEI homepage.