NOAA/PSL Catalog https://psl.noaa.gov/thredds/catalog/Datasets/gpcc/first_guess/catalog.html

Dataset Size Last Modified
     Folder  first_guess   --
         precip.first.mon.total.1x1.nc 28.00 Mbytes 2021-05-24T21:18:48Z

NOAA/PSL at NOAA PSL see Info
THREDDS Data Server [Version 4.6.15-SNAPSHOT - 2020-01-28T04:01:10+0000] Documentation