Data sources for indices:
ERSST.V5 : Huang, B., Peter W. Thorne, et. al, 2017: Extended Reconstructed Sea Surface Temperature version 5 (ERSSTv5), Upgrades, validations, and intercomparisons. J. Climate
Climatology : 1991-2020

WTIO  : SSTA averaged in [50ºE-70ºE, 10ºS-10ºN]
SETIO : SSTA averaged in [90ºE-110ºE, 10ºS-0]
DMI  = WTIO - SETIO

  Year   Month     WTIO      SETIO       DMI
  2023     6       0.22       0.31      -0.08
  2023     7       0.36       0.24       0.12
  2023     8       0.73       0.02       0.71
  2023     9       0.66      -0.18       0.84
  2023    10       0.71      -0.74       1.44
  2023    11       0.99      -0.52       1.50
  2023    12       1.14      -0.07       1.20
  2024     1       1.18       0.36       0.82
  2024     2       1.22       0.92       0.30
  2024     3       0.95       0.41       0.54