MEI Ranks (current update: 6 April 2018)

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 68 (69) numbers in each column, the lowest
number (1) would denote the strongest La Nina case for that bimonthly season, while the highest
number (68 or 69) 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, the lower and upper 30%iles) to define La Nina and El Nino, respectively, 
MEI ranks from 1-21 denote strong to weak La Nina conditions, while 48-68 (49-69) denote weak to
strong El Nino conditions. If one uses the quintile definition for (moderate or stronger) ENSO events,
MEI ranks from 1-14 would denote La Nina, while 55-68 (56-69)  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 (upper decile) ranks, such as 1-7 for La Nina, and 62-68 (63-69) for El Nino.

YEAR    DECJAN  JANFEB  FEBMAR  MARAPR  APRMAY  MAYJUN  JUNJUL  JULAUG  AUGSEP  SEPOCT  OCTNOV  NOVDEC
1950	11	10	6	7	3	5	5	10	17	22	10	6
1951	9	9	8	19	18	39	48	55	51	51	49	46
1952	48	40	38	37	21	11	21	20.5	41	43	25	35
1953	39	46	47	56	54	36	38	38	47	37	38	40
1954	37	39	44	16	2	2	4	5	11	7	11	10
1955	15	19	9	2	1	1	1	1	3	3	1	1
1956	4	6	5	5	5	3	6	9	7	5	15	11
1957	14	28	40	40	55	47	56	61	62	61	59	61
1958	64	63	63	61	51	51	49	44	36.5	41	43	52
1959	50	54	52	36	28	27	29	34	34	31	29	29
1960	31	31	30	27	20	17	19	26	22	26	26	25
1961	35	32	32	29	22	22	23	24	27	20	21	18
1962	8	12	17	8	9	8	13	14	19	18	18	24
1963	16	14	18	14	14	25	42	46	52.5	52	54	53
1964	56	49	25.5	18	6	7	3	4	8	10	8	15
1965	23	29	24	32	44	53	62	63	63	62	64	62
1966	63	61	55	51	24	21	28	36	33	32	37	31
1967	27	13	11	9	15	18	15	19	14	17	22	26
1968	19	16	19	10.5	7	9	14	31	38	45	47	43
1969	52	56	50	54	50	50	44	39	35	48	48	45
1970	46	47	46	28	25	13	11	11	9	11	13	7
1971	5	3	1	1	4	4	7	8	6	6	6	12
1972	21	27	25.5	23	42	57	65	65	64	64	65	65
1973	65	64	58	49.5	26	10	10	6	4	4	3	2
1974	1	1	2	3	8	12	12	13	16	12	7	16
1975	24	22.5	14	10.5	10	6	2	2	2	1	2	3
1976	3	5	7	6	13	38	47	50	60	55	44	47
1977	49	42	42	53	37	41	53	51	55	57	56	54
1978	55	57	59	35	17	14	18	27	25	33	40	44
1979	51	45	35	38	41	42	40	48	54	50	50	56
1980	53	52	54	59	58	54	52	41	39	40	41	37.5
1981	34	35	49	57	30.5	29	31	32	36.5	38	36	33
1982	33	36	39	30	43	56	63	64	65	66	67	68
1983	69	69	69	68	68	67	64	62	45	35	32	32
1984	29	25	43	41	30.5	28	30	28	32	34	24	19
1985	22	22.5	16	20	11	23	27	22	20	30	34.5	28
1986	30	33	37	25	40	37	41	54	61	56	55	59
1987	62	62	65	64	66	65	66	66	66	65	61	63
1988	59	53	51	43	32	15	8	7	5	8	5	5
1989	7	7	12	15	16	19	17	16	26	27	33	39
1990	41	51	60	47.5	48	43	33	35	43	42	42	41.5
1991	42	43	48	46	52	61	57	58	52.5	59	60	64
1992	66	66	67	66	65	64	58	45	46	49	46	50
1993	54	60	61	63	64	63	61	59	59	60	53	49
1994	45	41	45	49.5	47	49	54	53	58	63	63	60
1995	61	59	57	47.5	46	44	35	29	24	21	20	23
1996	20	24	28	22	27	33	25	20.5	23	25	31	27
1997	26	21	27	52	60	68	68	68	68	68	68	67
1998	68	68	68	67	67	62	39	23	15	15	12	14
1999	10	11	13	12	12	16	16	12	12	13	14	9
2000	6	8	10	21	35	31	26	30	28	23	17	21.5
2001	25	20	20	26	36	32	36	42	29	28	30	36
2002	38	34	29	44	56	55	50	57	57	58	57	58
2003	60	58	56	45	34	34	34	40	44	47	45	41.5
2004	44	44	33	42	45	40	46	49	48	46	52	51
2005	43	55	62	55	57	46	45	43	40	29	23	21.5
2006	28	26	21	17	29	45	51	52	56	54	62	55
2007	57	50	41	31	39	24	22	18	10	9	9	8
2008	12	4	4	13	19	35	32	25	18	16	19	17
2009	17	17	15	24	38	48	59	60	50	53	58	57
2010	58	65	64	62	49	20	9	3	1	2	4	4
2011	2	2	3	4	23	30	24	15	13	14	16	13
2012	13	18	23	34	53	52	60	47	42	36	39	37.5
2013	40	37	34	33	33	26	20	17	30	39	34.5	30
2014	32	30	36	39	59	59	55	56	49	44	51	48
2015	47	48	53	60	62	66	67	67	67	67	66	66
2016	67	67	66	65	63	60	37	37	31	24	28	34
2017	36	38	31	58	61	58	43	33	21	19	27	20
2018	18	15	22

Next update: 12 May 2018 or earlier if data feed comes through

Link to numerical MEI values is here.

Go back to MEI homepage.