MEI Ranks (current update: 8 February 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	39	37	37	21	11	21	20.5	41	43	25	35
1953	39	45	46	56	54	36	38	38	47	37	38	40
1954	37	38	43	16	2	2	4	5	11	7	11	10
1955	15	17	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	27	38	40	55	47	56	61	62	61	59	61
1958	64	62	62	61	51	51	49	44	36.5	41	43	52
1959	50	53	51	36	28	27	29	34	34	31	29	29
1960	31	29	29	27	20	17	19	26	22	26	26	25
1961	35	31	30	29	22	22	23	24	27	20	21	18
1962	8	12	16	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	48	24.5	18	6	7	3	4	8	10	8	15
1965	23	28	23	32	44	53	62	63	63	62	64	62
1966	63	60	53	51	24	21	28	36	33	32	37	31
1967	27	13	11	9	15	18	15	19	14	17	22	26
1968	19	15	19	10.5	7	9	14	31	38	45	47	43
1969	52	55	48	54	50	50	44	39	35	48	48	45
1970	46	46	45	28	25	13	11	11	9	11	13	7
1971	5	3	1	1	4	4	7	8	6	6	6	12
1972	21	25.5	24.5	23	42	57	65	65	64	64	65	65
1973	65	63	57	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	21	14	10.5	10	6	2	2	2	1	2	3
1976	3	4	7	6	13	38	47	50	60	55	44	47
1977	49	41	41.5	53	37	41	53	51	55	57	56	54
1978	55	56	58	35	17	14	18	27	25	33	40	44
1979	51	44	34	38	41	42	40	48	54	50	50	56
1980	53	51	54	59	58	54	52	41	39	40	41	37.5
1981	34	34	49	57	30.5	29	31	32	36.5	38	36	33
1982	33	35	39	30	43	56	63	64	65	66	67	68
1983	69	68	68	68	68	67	64	62	45	35	32	32
1984	29	24	41.5	41	30.5	28	30	28	32	34	24	19
1985	22	22	17	20	11	23	27	22	20	30	34.5	28
1986	30	32	36	25	40	37	41	54	61	56	55	59
1987	62	61	64	64	66	65	66	66	66	65	61	63
1988	59	52	50	43	32	15	8	7	5	8	5	5
1989	7	7	12	15	16	19	17	16	26	27	33	39
1990	41	50	59	47.5	48	43	33	35	43	42	42	41.5
1991	42	42	47	46	52	61	57	58	52.5	59	60	64
1992	66	65	66	66	65	64	58	45	46	49	46	50
1993	54	59	60	63	64	63	61	59	59	60	53	49
1994	45	40	44	49.5	47	49	54	53	58	63	63	60
1995	61	58	56	47.5	46	44	35	29	24	21	20	23
1996	20	23	27	22	27	33	25	20.5	23	25	31	27
1997	26	20	26	52	60	68	68	68	68	68	68	67
1998	68	67	67	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	19	20	26	36	32	36	42	29	28	30	36
2002	38	33	28	44	56	55	50	57	57	58	57	58
2003	60	57	55	45	34	34	34	40	44	47	45	41.5
2004	44	43	33	42	45	40	46	49	48	46	52	51
2005	43	54	61	55	57	46	45	43	40	29	23	21.5
2006	28	25.5	21	17	29	45	51	52	56	54	62	55
2007	57	49	40	31	39	24	22	18	10	9	9	8
2008	12	5	3	13	19	35	32	25	18	16	19	17
2009	17	16	15	24	38	48	59	60	50	53	58	57
2010	58	64	63	62	49	20	9	3	1	2	4	4
2011	2	2	4	4	23	30	24	15	13	14	16	13
2012	13	18	22	34	53	52	60	47	42	36	39	37.5
2013	40	36	32	33	33	26	20	17	30	39	34.5	30
2014	32	30	35	39	59	59	55	56	49	44	51	48
2015	47	47	52	60	62	66	67	67	67	67	66	66
2016	67	66	65	65	63	60	37	37	31	24	28	34
2017	36	37	31	58	61	58	43	33	21	19	27	20
2018	18

Next update: 10 March 2018 (or earlier if data feed comes through) 

Link to numerical MEI values is here.

Go back to MEI homepage.