MEI Ranks (last update: 4 October 2008) 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 ".5" value. Missing values are left blank. How can one interpret these ranks? Given that there are 58 (59) numbers in each column, the lowest number (1) would denote the strongest La Nina case for that bimonthly season, while the highest number (58 or 59) 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 1-19 denote weak to strong La Nina conditions, while 40-58 (41-59) 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 47-58 (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 51-58 (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 18 8 5 1951 8 7 7 20 22 37 46 50 50 43 42 39 1952 40 33 33 33 20 12 25 26.5 36 36 22 29 1953 33 40 40 52 50 33 39 33 42 32 32 33 1954 31 32 35 17 2 2 3 4 9 6 10 9 1955 13 15 8 2 1 1 1 1 2 2 1 1 1956 3 5 4 5 5 3 8 8 6 4 13 10 1957 11 23 34 41 51 45 50 53 54 52 50 51 1958 55 55 55 54 49 48.5 45 38 30 31 36 44 1959 42 47 45 31 29 29 22 30 29 26 25 25 1960 28 26 27 27 19 20 18 20 18 19 21 21 1961 30 27 28 28 21 25 20 18 22 16 19 15 1962 7 11 14 7 9 8 12 14 19 15 16 19 1963 14 13 16 13 15 26 36 44 45 44 47 45 1964 48 41 20 15 6 7 4 3 7 8 6 13 1965 19 25 22 30 42 50 54 55 55 53 55 54 1966 54 54 46 45 25 22 27 32 27 27 31 27 1967 22 12 9 8 16 18 13 15 12 14 18 22 1968 15 14 17 10 7 10 15 26.5 33 37 40 36 1969 46 48 42 50 48 46 40 35 34 38 41 37 1970 38 38 39 25 24 11 9 10 8 10 12 6 1971 4 2 1 1 3 4 6 7 5 5 5 11 1972 18 24 23 23 43 53 57 56 56 55 56 56 1973 57 56 50 47 26 9 10 5 3 3 4 2 1974 1 1 2 3 8 13.5 11 12 13 11 7 14 1975 21 19 13 9 10 6 2 2 1 1 2 3 1976 2 3 6 4 13 35 43 46 52 46 37 40 1977 41 35 37 49 37 43 49 45 47 47 49 46 1978 47 50 54 32 18 15 17 24 21 28 33 38 1979 43 39 29 36 38 41 35 43 48 42 43 48 1980 45 44 47 53 53 48.5 47 37 35 34 34 31 1981 27 29 43 51 31 27 28 28 31 33 30 28 1982 29 30 31 26 40 51 55 57 57 57 58 58 1983 59 59 59 59 59 58 56 54 40 30 26 26 1984 25 20 38 42 33 23.5 23 21 28 29 23 17 1985 17 18 15 19 11 23.5 24 17 17 25 29 24 1986 26 28 30 24 36 36 37 47 53 50 46 50 1987 53 53 56 56 58 57 58 58 58 56 52 55 1988 50 45 44 35 32 13.5 7 6 4 7 3 4 1989 6 6 10 14 14 17 16 13 24 21 28 32 1990 34 43 51 43 44 38 31 31 37 35 35 34 1991 36 36 41 38 46 52 52 51 44 48 51 53 1992 56 57 57 57 57 56 51 40 39 41 38 42 1993 44 52 53 55 56 55 53 52 51 51 45 41 1994 39 34 36 44 45 44 48 42 43 54 53 52 1995 51 49 48 37 41 42 33 29 20 17 17 20 1996 16 17 21 18 23 28 26 19 23 20 27 23 1997 23 21 24 46 54 59 59 59 59 58 57 57 1998 58 58 58 58 55 54 34 22 14 13 11 12 1999 10 10 12 11 12 16 14 11 11 12 14 7 2000 5 8 11 21 28 21 21 25 25 23 15 16 2001 20 16 18 22 34 31 32 36 26 22 24 30 2002 32 31 26 40 52 47 42 49 46 45 48 49 2003 52 51 49 39 30 30 30 34 38 40 39 35 2004 37 37 25 34 39 34 41 41 41 39 44 43 2005 35 46 52 48 47 39 38 39 32 24 20 18 2006 24 22 19 16 27 40 44 48 49 49 54 47 2007 49 42 32 29 35 19 19 16 10 9 9 8 2008 12 4 3 12 17 32 29 23 16 Next update: 8 November 2008 (or earlier) Link to numerical MEI values is here. Go back to MEI homepage.