MEI Index (updated: 7 December 2018) Bimonthly MEI values (in 1/1000 of standard deviations), starting with Dec1949/Jan1950, thru last month. More information on the MEI can be found on the MEI homepage. Missing values are left blank. Note that values can still change with each monthly update, even though such changes are typically smaller than +/-0.1. All values are normalized for each bimonthly season so that the 44 values from 1950 to 1993 have an average of zero and a standard deviation of "1". Responses to 'FAQs' can be found below this table: YEAR DECJAN JANFEB FEBMAR MARAPR APRMAY MAYJUN JUNJUL JULAUG AUGSEP SEPOCT OCTNOV NOVDEC 1950 -1.03 -1.133 -1.283 -1.071 -1.434 -1.412 -1.269 -1.042 -.631 -.441 -1.151 -1.235 1951 -1.049 -1.152 -1.178 -.511 -.374 .288 .679 .818 .726 .72 .694 .504 1952 .433 .138 .071 .224 -.307 -.756 -.305 -.374 .31 .265 -.351 -.098 1953 .044 .401 .277 .687 .756 .191 .382 .209 .483 .087 .078 .351 1954 -.036 -.027 .154 -.616 -1.465 -1.558 -1.355 -1.456 -1.159 -1.335 -1.124 -1.088 1955 -.74 -.669 -1.117 -1.621 -1.653 -2.247 -1.976 -2.05 -1.829 -1.738 -1.821 -1.846 1956 -1.408 -1.275 -1.371 -1.216 -1.304 -1.523 -1.244 -1.118 -1.35 -1.478 -1.024 -.993 1957 -.915 -.348 .108 .383 .813 .73 .926 1.132 1.117 1.068 1.138 1.268 1958 1.473 1.454 1.313 .991 .673 .812 .7 .421 .171 .203 .476 .691 1959 .553 .81 .502 .202 -.025 -.062 -.112 .111 .092 -.071 -.17 -.247 1960 -.287 -.253 -.082 .007 -.322 -.287 -.318 -.25 -.47 -.358 -.33 -.39 1961 -.15 -.235 -.073 .017 -.302 -.185 -.208 -.3 -.3 -.536 -.433 -.608 1962 -1.065 -.963 -.692 -1.04 -.89 -.87 -.683 -.538 -.56 -.671 -.617 -.482 1963 -.718 -.837 -.675 -.761 -.473 -.144 .404 .59 .734 .805 .837 .765 1964 .878 .481 -.256 -.545 -1.234 -1.15 -1.384 -1.486 -1.309 -1.216 -1.229 -.907 1965 -.536 -.329 -.259 .086 .464 .867 1.367 1.425 1.379 1.202 1.343 1.27 1966 1.307 1.186 .689 .515 -.178 -.193 -.116 .152 -.094 -.05 -.003 -.181 1967 -.462 -.898 -1.05 -1.03 -.448 -.236 -.492 -.391 -.627 -.677 -.424 -.357 1968 -.602 -.727 -.635 -.944 -1.093 -.812 -.503 -.104 .213 .424 .582 .367 1969 .67 .849 .458 .622 .674 .801 .49 .212 .162 .496 .659 .417 1970 .38 .432 .228 .014 -.099 -.636 -1.055 -1.007 -1.251 -1.088 -1.074 -1.203 1971 -1.204 -1.507 -1.79 -1.839 -1.429 -1.42 -1.207 -1.213 -1.467 -1.415 -1.311 -.969 1972 -.575 -.398 -.256 -.166 .423 .966 1.826 1.8 1.522 1.617 1.704 1.787 1973 1.723 1.515 .87 .491 -.099 -.758 -1.056 -1.334 -1.734 -1.66 -1.489 -1.826 1974 -1.912 -1.768 -1.743 -1.62 -1.048 -.694 -.75 -.664 -.628 -1.05 -1.24 -.886 1975 -.522 -.576 -.85 -.927 -.838 -1.148 -1.497 -1.712 -1.876 -1.978 -1.756 -1.732 1976 -1.587 -1.366 -1.213 -1.157 -.483 .276 .633 .654 1.018 .927 .49 .565 1977 .529 .29 .145 .552 .31 .414 .888 .684 .783 .97 .962 .877 1978 .777 .912 .935 .199 -.378 -.605 -.42 -.199 -.391 -.028 .175 .406 1979 .608 .379 .002 .301 .374 .429 .396 .615 .759 .655 .734 1.004 1980 .677 .601 .684 .912 .958 .911 .769 .329 .263 .192 .248 .111 1981 -.25 -.14 .455 .669 .189 -.024 -.026 -.09 .174 .101 -.039 -.126 1982 -.258 -.125 .1 .008 .443 .93 1.612 1.778 1.783 2.001 2.394 2.425 1983 2.677 2.931 3.008 2.812 2.498 2.235 1.793 1.159 .459 .024 -.132 -.17 1984 -.314 -.509 .151 .39 .18 -.049 -.054 -.155 -.12 -.006 -.35 -.585 1985 -.546 -.576 -.696 -.468 -.706 -.166 -.126 -.365 -.535 -.148 -.06 -.279 1986 -.293 -.183 .028 -.107 .353 .279 .401 .765 1.077 .96 .865 1.202 1987 1.249 1.218 1.716 1.855 2.107 1.958 1.878 1.973 1.851 1.617 1.257 1.293 1988 1.115 .716 .495 .389 .193 -.582 -1.109 -1.295 -1.526 -1.328 -1.453 -1.311 1989 -1.103 -1.241 -1.035 -.76 -.393 -.242 -.43 -.494 -.315 -.342 -.073 .131 1990 .243 .573 .951 .46 .652 .511 .147 .127 .366 .273 .383 .362 1991 .319 .323 .399 .449 .741 1.051 1.044 1.008 .739 .99 1.172 1.34 1992 1.747 1.886 1.985 2.247 2.085 1.735 1.045 .559 .488 .624 .569 .664 1993 .692 .99 .987 1.408 1.993 1.616 1.204 1.026 .966 1.045 .822 .595 1994 .352 .193 .159 .465 .58 .803 .904 .762 .893 1.389 1.282 1.251 1995 1.219 .959 .845 .453 .57 .507 .234 -.147 -.445 -.481 -.474 -.537 1996 -.597 -.566 -.236 -.391 -.041 .087 -.173 -.374 -.457 -.359 -.149 -.325 1997 -.48 -.605 -.248 .527 1.132 2.275 2.825 3.002 2.99 2.361 2.516 2.344 1998 2.455 2.777 2.751 2.658 2.206 1.336 .392 -.336 -.636 -.808 -1.071 -.908 1999 -1.039 -1.123 -.95 -.88 -.596 -.339 -.478 -.739 -.967 -.97 -1.041 -1.142 2000 -1.122 -1.189 -1.09 -.397 .251 .001 -.159 -.145 -.238 -.391 -.713 -.55 2001 -.496 -.649 -.548 -.05 .282 .052 .297 .332 -.174 -.276 -.151 .033 2002 .017 -.16 -.118 .401 .886 .932 .712 1.002 .881 .979 1.076 1.156 2003 1.214 .944 .83 .413 .214 .107 .177 .309 .46 .497 .563 .362 2004 .332 .37 -.036 .358 .558 .315 .571 .617 .558 .492 .794 .684 2005 .325 .816 1.057 .626 .885 .589 .519 .343 .296 -.179 -.385 -.55 2006 -.428 -.414 -.521 -.571 .045 .526 .716 .748 .8 .939 1.272 .965 2007 .985 .537 .125 .026 .348 -.155 -.248 -.442 -1.197 -1.217 -1.155 -1.178 2008 -1.006 -1.371 -1.552 -.858 -.345 .142 .088 -.269 -.58 -.699 -.588 -.646 2009 -.714 -.69 -.705 -.106 .326 .751 1.06 1.05 .707 .883 1.107 1.059 2010 1.066 1.526 1.462 .978 .658 -.228 -1.103 -1.671 -1.879 -1.892 -1.477 -1.558 2011 -1.719 -1.544 -1.554 -1.387 -.199 -.003 -.193 -.517 -.778 -.939 -.938 -.945 2012 -.98 -.675 -.382 .11 .757 .842 1.126 .607 .316 .069 .127 .111 2013 .103 -.068 -.026 .09 .205 -.094 -.314 -.481 -.155 .115 -.053 -.234 2014 -.27 -.259 .018 .295 1.001 1.046 .915 .937 .557 .421 .754 .566 2015 .417 .464 .614 .916 1.583 2.097 1.981 2.334 2.479 2.201 2.271 2.12 2016 2.216 2.17 1.963 2.094 1.752 1.053 .352 .167 -.118 -.385 -.209 -.11 2017 -.052 -.043 -.08 .744 1.445 1.039 .456 .009 -.478 -.568 -.285 -.576 2018 -.623 -.731 -.502 -.432 .465 .469 .076 .132 .509 .468 .698 (1) If you are trying to relate the MEI to monthly values of, say, precipitation, it may be expedient to use the MEI value of month(i-1) and month(i) as if it were the value for month(i) only. Since it takes a week or so for the global atmosphere to respond to tropical SST anomalies, the resulting lag is thus built into the analysis (I have verified this for southwest U.S. precipitation). (2) Next update: This is the final update for the MEI in its present incarnation (3) Are there MEI values available prior to 1950? YES, the link to the sister website for the MEI.ext is here. Numerical values for the MEI.ext are available here. (4) Why do I believe that the MEI is better for monitoring ENSO than the SOI or various SST indices? In brief, the MEI integrates more information than other indices, it reflects the nature of the coupled ocean-atmosphere system better than either component, and it is less vulnerable to occasional data glitches in the monthly update cycles. Now, if you are interested in ENSO impacts in a very specific part of the world, I would suggest that you obtain other ENSO indices as well and establish which one best fits your needs. For instance, in Australia, Darwin sea level pressure and/or the SOI may be more appropriate than the MEI. My claim here is that the MEI does a better job than other indices for the overall monitoring of the ENSO phenomenon, including, for instance, world-wide correlations with surface temperatures and rainfall. (5) I have been asked about MEI-like indices for the Indian Ocean, and at present I have no such project under way, nor do I know of any such data. (6) Given the integrative approach of the MEI, I am very hesitant to give out subsets of the data that make up the MEI (for instance, its SST or SLP components alone). Therefore, I will not honor requests of that nature. (7) If you are interested in MEI predictions, please contact me directly under my e-mail address: Klaus Wolter (klaus.wolter@noaa.gov). Link to ranked MEI values is here. Go back to MEI homepage.