MEI Ranks (current update: 9 August 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	49	55	51	51	49	46
1952	48	40	38	38	21	11	21	20.5	41	43	25	35
1953	39	46	47	58	54	36	39	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	42	56	48	57	61	62	61	59	61
1958	64	63	63	63	51	52	50	44	36.5	41	43	52
1959	50	54	52	37	28	27	29	34	34	31	29	29
1960	31	31	30	28	20	17	19	26	22	26	26	25
1961	35	32	32	31	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	43	46	52.5	52	54	53
1964	56	49	25.5	18	6	6	3	4	8	10	8	15
1965	23	29	24	33	44	54	63	63	63	62	64	62
1966	63	61	55	52	24	21	28	36	33	32	37	31
1967	27	13	11	9	15	19	15	19	14	17	22	26
1968	19	16	19	10	7	9	14	31	38	45	47	43
1969	52	56	50	55	52	50	45	39	35	48	48	45
1970	46	47	46	30	25.5	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	24	42	58	66	65	64	64	65	65
1973	65	64	58	51	25.5	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	11	10	7	2	2	2	1	2	3
1976	3	5	7	6	13	37	48	50	60	55	44	47
1977	49	42	42	54	37	41	54	51	55	57	56	54
1978	55	57	59	36	17	14	18	27	25	33	40	44
1979	51	45	35	40	41	42	41	48	54	50	50	56
1980	53	52	54	60	59	55	53	41	39	40	41	37.5
1981	34	35	49	57	31	29	31	32	36.5	38	36	33
1982	33	36	39	29	43	56	64	64	65	66	67	68
1983	69	69	69	69	69	68	65	62	45	35	32	32
1984	29	25	43	44	30	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	38	42	54	61	56	55	59
1987	62	62	65	65	67	66	67	66	66	65	61	63
1988	59	53	51	43	32	15	8	7	5	8	5	5
1989	7	7	12	15	16	18	17	16	26	27	33	39
1990	41	51	60	49	49	45	34	35	43	42	42	41.5
1991	42	43	48	47	53	61	58	58	52.5	59	60	64
1992	66	66	67	67	66	65	59	45	46	49	46	50
1993	54	60	61	64	65	64	62	59	59	60	53	49
1994	45	41	45	50	48	51	55	53	58	63	63	60
1995	61	59	57	48	47	44	36	29	24	21	20	23
1996	20	24	28	23	27	33	25	20.5	23	25	31	27
1997	26	21	27	53	61	69	69	68	68	68	68	67
1998	68	68	68	68	68	63	40	23	15	15	12	14
1999	10	11	13	12	12	16	16	12	12	13	14	9
2000	6	8	10	22	35	31	26	30	28	23	17	21.5
2001	25	20	20	27	36	32	37	42	29	28	30	36
2002	38	34	29	45	58	57	51	57	57	58	57	58
2003	60	58	56	46	34	34	35	40	44	47	45	41.5
2004	44	44	33	41	46	40	47	49	48	46	52	51
2005	43	55	62	56	57	47	46	43	40	29	23	21.5
2006	28	26	21	17	29	46	52	52	56	54	62	55
2007	57	50	41	32	39	24	22	18	10	9	9	8
2008	12	4	4	13	19	35	33	25	18	16	19	17
2009	17	17	15	26	38	49	60	60	50	53	58	57
2010	58	65	64	62	50	20	9	3	1	2	4	4
2011	2	2	3	4	23	30	24	15	13	14	16	13
2012	13	18	23	35	55	53	61	47	42	36	39	37.5
2013	40	37	34	34	33	26	20	17	30	39	34.5	30
2014	32	30	36	39	60	60	56	56	49	44	51	48
2015	47	48	53	61	63	67	68	67	67	67	66	66
2016	67	67	66	66	64	62	38	37	31	24	28	34
2017	36	38	31	59	62	59	44	33	21	19	27	20
2018	18	15	22	21	45	43	32

Next update: 8 September (or earlier) 2018 

Link to numerical MEI values is here.

Go back to MEI homepage.