These are the Global Precipitation Climatology Project (GPCP) mean precipitation rates (mm/hr) used in the Heymsfield et al. (2020, to be published) study
     Latitude     Rate (mm/hr)
      -88.75000        0.01398
      -86.25000        0.01477
      -83.75000        0.01494
      -81.25000        0.01491
      -78.75000        0.01994
      -76.25000        0.02719
      -73.75000        0.03178
      -71.25000        0.03666
      -68.75000        0.04813
      -66.25000        0.06098
      -63.75000        0.08545
      -61.25000        0.11012
      -58.75000        0.12755
      -56.25000        0.13154
      -53.75000        0.12849
      -51.25000        0.12290
      -48.75000        0.11765
      -46.25000        0.12155
      -43.75000        0.12390
      -41.25000        0.12431
      -38.75000        0.12176
      -36.25000        0.11219
      -33.75000        0.10591
      -31.25000        0.09997
      -28.75000        0.09288
      -26.25000        0.08671
      -23.75000        0.08048
      -21.25000        0.07913
      -18.75000        0.08350
      -16.25000        0.09571
      -13.75000        0.11145
      -11.25000        0.12642
       -8.75000        0.15253
       -6.25000        0.16714
       -3.75000        0.17191
       -1.25000        0.16238
        1.25000        0.17095
        3.75000        0.21687
        6.25000        0.25634
        8.75000        0.22644
       11.25000        0.16321
       13.75000        0.11511
       16.25000        0.09199
       18.75000        0.08174
       21.25000        0.07394
       23.75000        0.07075
       26.25000        0.07563
       28.75000        0.08116
       31.25000        0.09110
       33.75000        0.10060
       36.25000        0.10928
       38.75000        0.11615
       41.25000        0.11520
       43.75000        0.11131
       46.25000        0.10587
       48.75000        0.10299
       51.25000        0.10301
       53.75000        0.10002
       56.25000        0.10055
       58.75000        0.10001
       61.25000        0.08712
       63.75000        0.07903
       66.25000        0.06822
       68.75000        0.05933
       71.25000        0.04903
       73.75000        0.04241
       76.25000        0.03493
       78.75000        0.02809
       81.25000        0.02521
       83.75000        0.02160
       86.25000        0.02109
       88.75000        0.02195