Notice: This page is updated automatically on the first Thursday of each month. Because of the high frequency filter applied to the ERSSTv5 data (Huang et al. 2017, J.Climate), SST values may change up to two months after the initial "real time" value is posted. Therefore, the most recent index values should be considered an estimate.
DESCRIPTION: positve (red) and negitive (blue) periods based on a threshold of +/- 0.4oC , based on centered 30-year base periods updated every 10 years.
| Year | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
| 1950 | -0.31 | -0.5 | -0.54 | -0.5 | -0.05 | -0.44 | -0.82 | -1.24 | -1.53 | -1.55 | -1.21 | -1.51 |
| 1951 | -1.09 | -1.03 | -1.23 | -1.29 | -0.87 | -0.3 | 0.07 | 0.02 | -0.0 | -0.29 | -0.3 | 0.04 |
| 1952 | -0.14 | -0.31 | -0.53 | -0.38 | -0.54 | -0.72 | -0.71 | -0.89 | -0.59 | -0.63 | -0.75 | -1.02 |
| 1953 | -0.96 | -0.83 | -0.74 | -0.92 | -0.7 | -0.66 | -0.43 | -0.6 | -0.55 | -0.71 | -0.84 | -0.91 |
| 1954 | -0.97 | -0.83 | -0.99 | -1.24 | -1.47 | -1.6 | -1.93 | -1.16 | -0.79 | -0.22 | -0.35 | -0.43 |
| 1955 | -0.78 | -0.8 | -0.93 | -0.99 | -1.0 | -1.03 | -1.16 | -1.15 | -0.65 | -0.69 | -0.51 | -0.99 |
| 1956 | -1.13 | -1.1 | -1.14 | -1.01 | -1.05 | -1.24 | -1.37 | -0.93 | -0.77 | -1.35 | -1.29 | -1.55 |
| 1957 | -1.48 | -1.17 | -1.12 | -0.7 | -0.6 | -0.48 | -0.79 | -0.74 | -0.93 | -1.12 | -0.95 | -0.74 |
| 1958 | -0.94 | -0.57 | -0.87 | -0.95 | -2.29 | -2.47 | -1.84 | -1.68 | -1.47 | -1.28 | -1.39 | -0.84 |
| 1959 | -0.72 | -0.36 | -0.19 | -0.11 | -0.26 | -0.4 | -0.64 | -0.75 | -0.67 | -0.67 | -0.71 | -0.56 |
| Year | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
| 1960 | -0.79 | -0.79 | -0.97 | -0.76 | -0.6 | -0.74 | -0.34 | -0.31 | -0.44 | -0.34 | 0.1 | -0.04 |
| 1961 | -0.08 | -0.21 | -0.25 | -0.18 | 0.35 | -0.39 | -1.12 | -0.92 | -0.71 | -0.45 | -0.27 | -0.46 |
| 1962 | -0.32 | -0.43 | -0.61 | -0.46 | -0.39 | -0.44 | -0.58 | -0.6 | -0.82 | -0.41 | -0.42 | -0.38 |
| 1963 | -0.35 | -0.29 | -0.22 | -0.14 | 0.34 | 0.88 | 1.03 | 0.86 | 0.42 | 0.16 | 0.05 | 0.13 |
| 1964 | 0.21 | -0.24 | -0.15 | -0.48 | -0.94 | -1.31 | -0.97 | -1.23 | -1.51 | -1.89 | -1.72 | -1.58 |
| 1965 | -1.23 | -1.12 | -0.59 | -0.59 | -0.65 | -1.07 | -1.36 | -1.09 | -0.7 | -1.18 | -1.3 | -1.21 |
| 1966 | -0.75 | -0.73 | -0.84 | -0.51 | -0.06 | 0.61 | 0.14 | -0.78 | -0.8 | -0.68 | -0.39 | -0.03 |
| 1967 | -0.26 | -0.13 | -0.81 | -0.31 | -0.56 | -1.47 | -1.59 | -1.15 | -1.21 | -1.51 | -1.41 | -1.27 |
| 1968 | -1.06 | -0.98 | -0.97 | -0.71 | -0.1 | 0.66 | 0.84 | -0.05 | -0.27 | -0.14 | -0.13 | -0.3 |
| 1969 | -0.38 | -0.2 | -0.29 | -0.21 | -0.34 | -0.87 | -1.24 | -1.21 | -1.23 | -1.01 | -1.05 | -0.77 |
| Year | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
| 1970 | -0.8 | -0.57 | -0.52 | -0.64 | -0.49 | -0.93 | -0.65 | -0.38 | -0.53 | -0.74 | -0.6 | -0.98 |
| 1971 | -0.87 | -0.89 | -0.69 | -0.35 | 0.15 | -0.22 | -0.86 | -1.0 | -0.89 | -0.88 | -1.43 | -1.39 |
| 1972 | -1.03 | -0.67 | -0.96 | -0.68 | -0.48 | -0.39 | -0.38 | -0.87 | -0.73 | -0.5 | -0.12 | 0.2 |
| 1973 | 0.21 | 0.36 | -0.08 | 0.16 | 0.26 | -0.14 | -0.06 | 0.3 | 0.21 | -0.03 | -0.24 | -0.31 |
| 1974 | -0.32 | -0.43 | -0.23 | -0.08 | 0.29 | 0.46 | 0.23 | -0.13 | -0.63 | -0.88 | -0.77 | -0.96 |
| 1975 | -0.83 | -0.59 | -0.65 | -0.45 | -0.14 | -0.08 | -0.31 | -0.85 | -0.66 | -0.63 | -0.5 | -0.61 |
| 1976 | -0.6 | -0.74 | -0.83 | -1.14 | -1.06 | -1.11 | -1.4 | -1.0 | -1.06 | -1.06 | -1.3 | -1.01 |
| 1977 | -1.0 | -0.66 | -0.87 | -0.62 | -0.67 | -0.56 | -0.71 | -0.52 | -0.17 | -0.62 | -0.47 | -0.45 |
| 1978 | -0.64 | -0.91 | -1.22 | -0.97 | -1.01 | -0.9 | -0.63 | -0.88 | -0.87 | -0.83 | -0.79 | -0.58 |
| 1979 | -0.54 | -0.62 | -0.65 | -0.39 | -0.32 | -0.04 | 0.15 | 0.14 | -0.0 | -0.23 | 0.07 | -0.16 |
| Year | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
| 1980 | -0.45 | -0.57 | -0.82 | -0.32 | -0.23 | -0.52 | -0.11 | -0.5 | -0.21 | -0.68 | -0.48 | -0.96 |
| 1981 | -0.8 | -0.54 | -0.9 | -0.7 | -0.36 | -0.11 | -0.15 | 0.07 | 0.18 | 0.45 | 0.32 | 0.23 |
| 1982 | 0.04 | 0.05 | -0.01 | -0.36 | -0.37 | -0.68 | -0.99 | -0.97 | -0.66 | -0.52 | -0.87 | -0.9 |
| 1983 | -0.33 | -0.17 | -0.31 | -0.58 | -1.02 | -0.94 | -0.55 | -0.4 | -0.42 | -0.64 | -0.34 | -0.41 |
| 1984 | -0.32 | 0.08 | 0.26 | -0.12 | 0.01 | 0.27 | 0.29 | 0.59 | 0.71 | 0.09 | 0.17 | 0.01 |
| 1985 | -0.25 | -0.04 | -0.46 | -0.22 | 0.01 | -0.31 | 0.15 | -0.1 | -0.26 | -0.01 | -0.15 | -0.12 |
| 1986 | -0.55 | -0.35 | -0.3 | -0.06 | -0.33 | 0.31 | -0.22 | -0.33 | -0.05 | -0.66 | -1.04 | -0.57 |
| 1987 | -0.68 | -0.31 | -0.16 | -0.09 | -0.07 | 0.41 | 1.04 | 0.64 | 0.56 | 0.06 | 0.37 | 0.14 |
| 1988 | 0.15 | 0.09 | 0.33 | 0.49 | 0.79 | 0.81 | 1.17 | 0.82 | 0.22 | 0.23 | -0.1 | -0.07 |
| 1989 | -0.34 | -0.29 | -0.78 | -0.18 | 0.04 | 0.34 | 0.33 | 0.41 | 0.35 | 0.16 | -0.12 | -0.62 |
| Year | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
| 1990 | -0.63 | -0.43 | -0.27 | -0.12 | -0.51 | -0.02 | -0.32 | -0.39 | -0.07 | 0.19 | -0.23 | -0.13 |
| 1991 | -0.11 | -0.45 | -0.13 | -0.02 | 0.17 | 0.91 | 0.41 | -0.18 | -0.48 | -0.55 | -0.96 | -0.94 |
| 1992 | -0.64 | -0.44 | -0.3 | -0.69 | -1.17 | -1.03 | -0.76 | -0.77 | -0.61 | -0.53 | -0.77 | -0.44 |
| 1993 | -0.45 | -0.66 | -0.84 | -0.12 | -0.24 | -0.22 | -0.25 | -0.53 | 0.38 | 0.37 | 0.75 | 0.44 |
| 1994 | 0.06 | -0.39 | -0.24 | 0.18 | -0.05 | -0.34 | -0.78 | -0.21 | -0.61 | -0.29 | 0.06 | 0.09 |
| 1995 | 0.02 | 0.03 | 0.3 | 0.19 | 0.54 | 0.59 | 0.5 | 0.09 | -0.09 | -0.43 | 0.02 | -0.34 |
| 1996 | -0.36 | -0.35 | -0.1 | 0.21 | 0.58 | 1.02 | 0.48 | 0.05 | -0.47 | -0.44 | -0.64 | -0.76 |
| 1997 | -0.84 | -0.82 | -0.87 | -0.9 | -0.54 | -1.14 | -0.45 | -0.21 | -0.3 | 0.21 | 0.13 | 0.46 |
| 1998 | 0.55 | 0.57 | 0.22 | -0.0 | -0.03 | 0.64 | 0.48 | 0.46 | 0.38 | 0.23 | 0.54 | 0.15 |
| 1999 | -0.12 | -0.2 | 0.07 | 0.22 | 0.65 | 0.3 | 1.02 | 0.47 | -0.14 | -0.22 | -0.29 | 0.11 |
| Year | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
| 2000 | -0.23 | -0.01 | -0.04 | -0.23 | -0.01 | -0.5 | -0.53 | -0.53 | -0.48 | -0.55 | -0.59 | -0.34 |
| 2001 | -0.36 | -0.23 | 0.12 | 0.15 | 0.1 | -0.06 | -0.28 | -0.24 | -0.05 | -0.01 | -0.7 | -1.05 |
| 2002 | -0.74 | -0.38 | -0.34 | -0.11 | -0.01 | 0.26 | 0.12 | 0.09 | -0.24 | -0.24 | -0.14 | 0.25 |
| 2003 | 0.16 | 0.27 | 0.42 | 0.02 | -0.31 | -0.11 | 0.51 | 0.43 | 0.38 | 0.08 | 0.22 | 0.49 |
| 2004 | 0.44 | 0.17 | -0.07 | -0.66 | -0.54 | -0.45 | -0.2 | 0.06 | 0.27 | -0.13 | 0.13 | 0.05 |
| 2005 | 0.14 | 0.13 | 0.07 | -0.24 | -0.98 | -1.32 | -0.85 | -0.26 | -0.03 | 0.18 | 0.04 | 0.03 |
| 2006 | 0.01 | 0.18 | -0.09 | -0.1 | 0.1 | 0.25 | 0.1 | -0.27 | 0.01 | -0.11 | 0.04 | 0.09 |
| 2007 | -0.07 | -0.03 | -0.39 | -0.29 | 0.17 | 0.3 | 0.32 | 0.08 | 0.46 | 0.15 | 0.04 | 0.17 |
| 2008 | 0.19 | 0.18 | 0.29 | 0.19 | 0.28 | 0.64 | 0.43 | 0.58 | 0.28 | 0.05 | 0.36 | 0.39 |
| 2009 | 0.26 | 0.16 | 0.41 | 0.21 | 0.69 | -0.19 | -0.46 | -0.58 | -0.39 | -0.41 | -0.43 | -0.04 |
| Year | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
| 2010 | 0.11 | 0.35 | 0.25 | 0.29 | 0.36 | 0.62 | 0.2 | 0.32 | 0.44 | 0.6 | 0.59 | 0.3 |
| 2011 | 0.23 | 0.36 | 0.22 | 0.34 | -0.11 | -0.67 | -0.48 | -0.1 | 0.04 | 0.14 | -0.11 | -0.7 |
| 2012 | -0.69 | -0.71 | -0.54 | -0.64 | -0.57 | -0.42 | -0.29 | -0.24 | -0.18 | -0.01 | -0.11 | -0.08 |
| 2013 | 0.32 | 0.42 | 0.25 | 0.08 | -0.44 | -0.11 | -0.41 | -0.3 | -0.47 | -0.36 | -0.39 | -0.42 |
| 2014 | -0.29 | -0.14 | -0.11 | 0.13 | 0.33 | -0.03 | -0.5 | -0.32 | -0.2 | -0.08 | -0.77 | -0.54 |
| 2015 | -0.06 | 0.01 | 0.03 | 0.18 | 0.19 | -0.25 | -0.27 | -0.31 | -0.13 | 0.04 | 0.35 | 0.34 |
| 2016 | 0.26 | -0.06 | 0.12 | 0.19 | -0.09 | 0.48 | 0.93 | 0.65 | 0.52 | 0.67 | 0.75 | 0.63 |
| 2017 | 0.29 | 0.28 | 0.26 | 0.41 | 0.22 | 0.22 | 0.15 | 0.69 | 0.43 | 0.3 | 0.03 | 0.07 |
| 2018 | 0.3 | 0.15 | -0.23 | -0.02 | 0.31 | 0.53 | 0.63 | 0.67 | 0.69 | 0.61 | 0.73 | 0.56 |
| 2019 | 0.49 | 0.56 | 0.78 | 0.54 | 0.23 | 0.1 | 0.12 | 0.34 | 0.54 | 0.38 | 0.96 | 1.16 |
| Year | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
| 2020 | 1.17 | 1.04 | 0.5 | 0.48 | 0.15 | -0.05 | 0.11 | 0.09 | 0.05 | 0.37 | 0.15 | -0.12 |
| 2021 | -0.19 | -0.08 | -0.22 | -0.17 | 0.46 | 1.12 | 1.36 | 1.31 | 0.93 | 0.68 | 0.56 | 0.23 |
| 2022 | 0.22 | 0.12 | 0.24 | 0.21 | 0.06 | 0.43 | -0.06 | 0.08 | 0.22 | 0.26 | 0.03 | 0.15 |
| 2023 | 0.57 | 0.47 | 0.26 | 0.49 | 0.7 | 0.14 | 0.42 | 0.43 | 0.42 | 0.38 | 0.7 | 1.12 |
| 2024 | 0.46 | 0.8 | 1.37 | 1.17 | 0.42 | -0.07 | -0.38 | 0.13 | 0.39 | 0.44 | 0.41 | 0.81 |
| 2025 | 0.62 | 0.86 |
Climatology : 1991-2020
TNA : SSTA averaged in [60ºW-30ºW, 5ºN-20ºN]
TSA : SSTA averaged in [30ºW-10ºE, 20ºS-0]
MGI = TNA - TSA
ATL3 : SSTA averaged in [20ºW-0, 2.5ºS-2.5N]