MEI Ranks (last update: 3 February 2015)

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 64-65 numbers in each column, the lowest
number (1) would denote the strongest La Nina case for that bimonthly season, while the highest
number (65 or 66) 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 1-20
denote strong to weak La Nina conditions, while 46-65 (or 47-66) denote weak to strong El Nino conditions.
If one uses the quintile definition for (moderate or stronger) ENSO events, MEI ranks from 1-13
would denote La Nina, while 53-65 (54-66) would denote El Nino.  Finally, the comparison figures on this
website refer to strong ENSO events, such as might be defined by the top 7 (one tenth or smaller)
ranks, such as 1-7 for La Nina, and 59-65 (60-66) 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	6
1951	10	10	8	22	20	42	49	53	50.5	49	48	44
1952	45	38	37.5	39	21.5	13	22	29	40	41	25	33
1953	37	44	45	57	56	37	40	38	46	34.5	36	38
1954	35	37	43	19	3	2	4	5	10	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	41	45	57	48	54	59	60	59	57	59
1958	62	60	60	60	52	53	48	42	34	38.5	42	50
1959	48	52	50	37	29	32	25	33	32	29	27	29
1960	30	31	32	31.5	19	21	20	24	22	24	26	24
1961	34	30	31	31.5	21.5	27	26	25	26	19	21	18
1962	9	12	17	9.5	9	8	13	15	19	18	19	23
1963	17	14	18	15	13.5	29	42	45	49	50	52	51
1964	54	46	23	17	6	7	3	4	8	9	8	16
1965	24	28	27	34	46	56	60	61	61	60	62	61
1966	61	59	52	53	24	24	27	36	30	31	35	30
1967	26	13	11	7	15	18	14	19	15	17	22	25
1968	20	18	19	11	7	10	15	31	36	43	44.5	41
1969	50	53	48	55	50	49	41	35	33	45	46	42
1970	44	45	44	27	26	11	10	11	9	11	13	7
1971	5	3	1	1	2	4	6	8	6	6	6	12
1972	19	26	26	23	43	60	64	62	62	63	63	63
1973	63	61	54	50	27	9	11	7	4	4	4	1
1974	1	1	2	2	8	14	12	13	17	12	7	15
1975	21	21	14	12	10	6	2	3	2	1	2	3
1976	3	5	7	5	13.5	39	46	47	58	52	41	45
1977	47	40	39	52	39	44	53	49	54	55	54	52
1978	53	54	57	36	17	15	19	27	24	30	38	43
1979	49	43	34	40	41	40	38	46	50.5	47	49	55
1980	51	49	51	59	58	50	50	40	39	38.5	39	36
1981	33	34	47	56	33	31	31	32	35	34.5	34	32
1982	32	36	37.5	29	42	57	61	63	63	64	64	65
1983	66	65	65	65	65	64	62	60	42	32	29	31
1984	28	24	40	43	34	25	29	28	31	33	24	19
1985	22	22	15	21	11	28	28	22	20	28	33	28
1986	31	33	35	24	38	38	39	52	59	54	53	57
1987	60	58	62	62	62	63	63	64	64	62	59	60
1988	56	50	49	41	31	12	9	6	5	8	5	5
1989	7	6	13	14	16	20	17	16	25	25	32	37
1990	39	48	56	46	49	41	34	34	41	40	40	40
1991	42	41	46	49	51	58	57	58	48	56	58	62
1992	64	63	63	63	63	62	56	43	45	48	44.5	48
1993	52	57	58	61	61	61	58	57	57	58	51	46
1994	43	39	42	48	47	47	52	50	56	61	60	58
1995	59	56	55	47	45	43	35	26	23	20	20	22
1996	18	23	24	20	25	33	23	21	21	22.5	30	26
1997	25	20	25	51	60	65	65	65	65	65	65	64
1998	65	64	64	64	64	59	37	20	14	15	9.5	13
1999	8	9	12	9.5	12	16	16	12	12	13	14	8
2000	6	8	9	18	35	26	24	30	27	22.5	17	21
2001	23	16	20	26	37	30	36	41	29	26	28	34
2002	36	32	28	44	55	52	45	55	55	53	55	56
2003	58	55	53	42	30	34	33	37	43	46	43	39
2004	41	42	30	38	44	36	43	48	47	44	50	49
2005	40	51	59	54	54	45	44	39	37	27	23	20
2006	27	25	21	16	28	46	47	51	53	51	61	53
2007	55	47	36	28	36	19	21	18	11	10	9.5	9
2008	13	4	3	13	18	35	32	23	16	16	18	17
2009	16	15	16	25	40	55	55	56	52	57	56	54
2010	57	62	61	58	48	17	8	2	1	2	3	4
2011	2	2	4	4	23	23	30	17	13	14	16	14
2012	11	17	22	33	53	54	59	44	38	37	37	35
2013	38	35	29	30	32	22	18	14	28	36	31	27
2014	29	29	33	35	59	51	51	54	44	42	47	47
2015	46

Next update: 7 March 2015 (or earlier)
Link to numerical MEI values is here.

Go back to MEI homepage.