Annual mean cold tongue index sea surface temperature (0.01 C)
Averages taken from April to March of the following year
and ascribed to the year of the April.
For example, the average from April 1950 to March 1951
is -0.57 C.
        +0    1    2    3    4    5    6    7    8    9
 1950  -57   68   -3   24  -78  -94  -26  101   15    1
 1960  -10  -39  -42   32  -44  106  -24  -52   28   55
 1970  -73  -36  113  -81  -24  -58   70   10  -18   27
 1980   -3  -10  144   42  -60  -46   46   78  -97  -28
 1990    0   82   34   47   40  -53  -34  150 -101 -111
 2000  -71  -24   61   -7   29