MEI Ranks (last update: 4 August 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 65-66 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	7	4	5	5	10	18	21	11	6
1951	10	10	8	22	20	40	46	53	50.5	49	48	44
1952	45	38	36	37.5	21	11	21	29	40	41	25	33
1953	37	44	45	57	54	36	38	38	46	34.5	36	38
1954	35	37	43	19	2	2	4	5	10	7	12	10
1955	15	18	10	3	1	1	1	1	3	3	1	2
1956	4	7	5	6	5	3	6	9	7	5	15	11
1957	14	27	41	44	57	47	53	59	60	59	57	59
1958	62	61	61	61	51	50	49	42	34	38.5	42	50
1959	48	53	50	37.5	29	31	27.5	33	32	29	27	29
1960	30	30	32	31	19	18	20	24	22	24	26	24
1961	34	29	31	32	22	24	23	25	26	19	21	18
1962	9	12	17	10	9	8	13	15	19	18	19	23
1963	17	14	18	15	13	26	41	45	49	50	52	51
1964	54	46	23	17	6	7	3	4	8	9	8	16
1965	24	28	24	34	44	53	60	61	61	60	62	61
1966	61	59	53	52	24	23	27.5	36	30	31	35	30
1967	26	13	12	9	15	19	15	19	15	17	22	25
1968	20	19	20	13	7	10	14	31	36	43	44.5	41
1969	50	54	47	55	50	49	42	35	33	45	46	42
1970	44	45	44	27	25	12	9	11	9	11	13	7
1971	5	3	1	1	3	4	7	8	6	6	6	12
1972	19	26	25	23	43	58	63	62	62	63	63	63
1973	63	62	55	49	26	9	10	7	4	4	4	1
1974	1	1	2	2	8	13.5	12	13	17	12	7	15
1975	21	20	14	11	10	6	2	3	2	1	2	3
1976	3	5	7	5	14	39	45	47	58	52	41	45
1977	47	40	38	53	38	42	51	49	54	55	54	52
1978	53	55	58	35	17	15	17	27	24	30	38	43
1979	49	43	33	40	41	41	39	46	50.5	47	49	55
1980	51	50	52	59	58	51	50	40	39	38.5	39	36
1981	33	35	49	56	34	30	31	32	35	34.5	34	32
1982	32	36	39	29	42	56	61	63	63	64	64	65
1983	66	66	66	66	66	65	62	60	42	32	29	31
1984	28	24	40	41	32	27	29	28	31	33	24	19
1985	22	21	15	21	11	25	26	22	20	28	33	28
1986	31	33	35	26	39	38	40	52	59	54	53	57
1987	60	60	63	63	63	63	64	64	64	62	59	60
1988	56	51	48	42	30	13.5	8	6	5	8	5	5
1989	7	6	13	14	16	20	18	16	25	25	32	37
1990	39	49	57	46	49	44	33	34	41	40	40	40
1991	42	41	46	50	53	59	57	58	48	56	58	62
1992	64	64	64	64	64	62	56	43	45	48	44.5	48
1993	52	58	59	62	62	61	58.5	57	57	58	51	46
1994	43	39	42	48	47	48	52	50	56	61	60	58
1995	59	57	56	47	46	43	35	26	23	20	20	22
1996	18	23	27	20	27	33	24	21	21	22.5	30	26
1997	25	22	26	51	60	66	66	65	65	65	65	64
1998	65	65	65	65	65	60	37	20	14	15	9.5	13
1999	8	9	11	8	12	16	16	12	12	13	14	8
2000	6	8	9	18	35	29	25	30	27	22.5	17	21
2001	23	16	19	24.5	36	32	36	41	29	26	28	34
2002	36	32	28	45	56	55	48	55	55	53	55	56
2003	58	56	54	43	31	34	34	37	43	46	43	39
2004	41	42	30	39	45	37	44	48	47	44	50	49
2005	40	52	60	54	55	45	43	39	37	27	23	20
2006	27	25	21	16	28	46	47	51	53	51	61	53
2007	55	48	37	28	37	21	22	18	11	10	9.5	9
2008	13	4	3	12	18	35	32	23	16	16	18	17
2009	16	15	16	24.5	40	52	55	56	52	57	56	54
2010	57	63	62	58	48	17	11	2	1	2	3	4
2011	2	2	4	4	23	28	30	17	13	14	16	14
2012	11	17	22	33	52	54	58.5	44	38	37	37	35
2013	38	34	29	30	33	22	19	14	28	36	31	27
2014	29	31	34	36	59	57	54	54	44	42	47	47
2015	46	47	51	60	61	64	65

Next update: 5 September 2015 (or earlier)

Link to numerical MEI values is here.

Go back to MEI homepage.