This dataset depends on the following independent variable (i.e, grid):
grid: /C (ids) unordered [ (Below) (Normal) (Above)] :grid
grid: /S (months since 1960-01-01) ordered (0000 1 Feb 2021) to (0000 1 Jul 2022) by 1.0 N= 18 pts :grid
so there will be 54 links below for the different files.
You may want to get a utility like wget which can download sets of files. For example (all one line)
wget -r -l2 -nd --no-parent -e robots=off -v --relative 'http://digilib.icpac.net/SOURCES/.ICPAC/.Forecasts/.CPT/.Rainfallv2/.Seasonal/.Forecast/.Prob/downloadsarcinfo.html'
single quotes are necessary in unix to protect the url from expansion; probably necessary in other cases as well