1983 January, test month
A test month is January 1983 where an interest is El Nino. This was actually a very large on, so large it is has left a clear imprint in the LoD (Length of Day) earth rotation dataset. Thermally it turned into low key, apparently because of confounding volcanic eruption.
Below here are test plots. RSS upper stratosphere is missing because the dataset did not start until 1987.
Out of interest note the Stratosphere temperature inversion.