MEI Ranks (last update: 5 June 2009) 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 59 or 60 numbers in each column, the lowest number (1) would denote the strongest La Nina case for that bimonthly season, while the highest number (59 or 60) 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 terciles (or: thirds) to define La Nina, near-normal, and El Nino, MEI ranks from 1-20 denote weak to strong La Nina conditions, while 41-60 (or 40-59) 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 49-60 (48-59) would denote El Nino. Finally, the comparison figures on this website refer to strong ENSO events, such as might be defined by the top 8 (one seventh or smaller) ranks, such as 1-8 for La Nina, and 53-60 (52-59) for El Nino. YEAR DECJAN JANFEB FEBMAR MARAPR APRMAY MAYJUN JUNJUL JULAUG AUGSEP SEPOCT OCTNOV NOVDEC 1950 9 9 5 6 4 5 5 9 15 19 8 5 1951 8 7 7 20 22 37 46 50 50 44 43 40 1952 41 34 33 34 20 12 25 26.5 36 37 23 30 1953 34 41 41 53 51 33 39 33 42 33 33 34 1954 32 33 35 17 2 2 3 4 9 7 11 9 1955 13 16 8 2 1 1 1 1 2 2 1 1 1956 3 5 4 5 5 3 8 8 6 4 13 11 1957 11 24 37 43 52 45 50 53 54 53 51 52 1958 56 56 56 55 50 48.5 45 38 30 32 38 45 1959 43 48 46 33 29 29 22 30 29 27 26 26 1960 28 27 28 28 19 20 18 20 18 20.5 22 22 1961 31 28 29 30 21 25 20 18 22 17 21 15 1962 7 11 14 7 9 8 12 14 19 16 16 20 1963 14 13 17 13 15 26 36 44 45 45 48 46 1964 49 42 21 15 6 7 4 3 7 8 6 13 1965 20 26 23 31 43 50 54 55 55 54 56 55 1966 55 55 47 46 25 22 27 32 27 28 32 28 1967 23 12 9 8 16 18 13 15 12 15 19 23 1968 16 14 18 11 7 10 15 26.5 33 38 41 38 1969 47 49 43 51 49 46 40 35 34 39 42 37 1970 39 40 40 26 24 11 9 10 8 10 12 6 1971 4 2 1 1 3 4 6 7 5 5 5 10 1972 19 25 24 24 44 53 57 56 56 56 57 57 1973 58 57 51 48 26 9 10 5 3 3 4 2 1974 1 1 2 3 8 13.5 11 12 13 11 7 14 1975 22 20 13 9 10 6 2 2 1 1 2 3 1976 2 3 6 4 13 35 43 46 52 47 37 41 1977 42 36 38 50 38 43 49 45 47 49 50 47 1978 48 51 55 32 18 15 17 24 21 29 34 39 1979 44 39 30 37 39 41 35 43 48 43 44 49 1980 46 45 48 54 54 48.5 47 37 35 35 35 32 1981 29.5 29 44 52 31 27 28 28 31 34 31 29 1982 29.5 31.5 32 27 41 51 55 57 57 58 59 59 1983 60 60 60 60 60 58 56 54 40 31 27 27 1984 26 21 39 42 33 23.5 23 21 28 30 24 18 1985 18 19 16 19 11 23.5 24 17 17 26 30 25 1986 27 30 31 25 36 36 37 47 53 51 47 53 1987 54 54 57 57 59 57 58 58 58 57 53 56 1988 51 46 45 36 32 13.5 7 6 4 6 3 4 1989 6 6 11 14 14 17 16 13 24 22 29 33 1990 35 44 52 44 45 38 31 31 37 36 36 36 1991 37 37 42 39 47 52 52 51 44 50 52 54 1992 57 58 58 58 58 56 51 40 39 42 39 43 1993 45 53 54 56 57 55 53 52 51 52 46 42 1994 40 35 36 45 46 44 48 42 43 55 54 51 1995 52 50 50 38 42 42 33 29 20 18 18 21 1996 17 18 22 18 23 28 26 19 23 20.5 28 24 1997 24 22 25 47 55 59 59 59 59 59 58 58 1998 59 59 59 59 56 54 34 22 14 13 10 12 1999 10 10 12 10 12 16 14 11 11 12 14 7 2000 5 8 10 21 28 21 21 25 25 23.5 15 16 2001 21 17 20 23 34 31 32 36 26 23.5 25 31 2002 33 31.5 26 41 53 47 42 49 46 46 49 50 2003 53 52 49 40 30 30 30 34 38 41 40 35 2004 38 38 27 35 40 34 41 41 41 40 45 44 2005 36 47 53 49 48 39 38 39 32 25 20 19 2006 25 23 19 16 27 40 44 48 49 48 55 48 2007 50 43 34 29 35 19 19 16 10 9 9 8 2008 12 4 3 12 17 32 29 23 16 14 17 17 2009 15 15 15 22 37 Next update: 7 July 2009 (probably earlier) Link to numerical MEI values is here. Go back to MEI homepage.