@DanielWatkins Hi, the IGRA-2 derived is missing division by 10 in "calculated relative humidity" and is thus, overestimating the value by a tens extra.

I've checked with the following raw data and for a couple of other stations as well.

#RSM00023022 1998 01 06 12 9999 27 214 80600 1739 42-99999-99999-99999-99999 98258 278-99999-99999-99999-99999 32 15 -13 34-99999-99999
102100 55 55 2497 -28 2482 69 2497 2482 756 929 -99999 813 -354 0 -208 -30 -153 322
100100 -99999 199 2493 0 2492 91 2493 2492 683 896 -99999 762 0 -30 0 -52 0 316
100000 210 206 2493 52 2493 145 2493 2493 683 896 -99999 762 -93 -30 -109 -52 -44 315
97400 -99999 403 2503 -91 2521 10 2503 2522 728 979 -99999 744 15 -99999 -99999 -99999 -99999 306
94800 -99999 600 2485 144 2523 244 2485 2523 623 834 -99999 747 -11 -99999 -99999 -99999 -99999 300
92500 780 780 2511 167 2567 292 2511 2568 783 1051 -99999 745 333 -92 -74 -77 -63 291
92200 -99999 804 2515 20 2574 122 2515 2574 819 1088 -99999 753 -279 -99999 -99999 -99999 -99999 289
85000 1400 1404 2527 30 2647 135 2527 2647 709 1208 -99999 587 8 -138 -22 -116 -17 265
80600 -99999 1794 2539 -64 2700 37 2539 2701 790 1339 -99999 590 -18 -99999 -99999 -99999 -99999 251
70000 2830 2828 2473 -63 2738 39 2473 2739 427 748 -99999 571 107 -169 31 -141 6 222
62900 -99999 3596 2425 -57 2768 48 2425 2769 313 479 -99999 653 -184 -99999 -99999 -99999 -99999 203
53000 -99999 4794 2357 -74 2825 27 2357 2826 106 246 -99999 432 96 -109 7 -130 59 175
50000 5200 5193 2327 -58 2836 50 2327 2836 85 181 -99999 471 -21 -106 21 -106 -16 167
40000 6690 6691 2241 -60 2911 50 2241 2911 31 71 -99999 440 -20 -75 35 -130 5 139
38200 -99999 6991 2223 -27 2926 96 2223 2926 25 58 -99999 434 -10 -99999 -99999 -99999 -99999 134
30000 8550 8548 2181 -41 3076 82 2181 3076 15 35 -99999 418 -16 -10 23 -120 -46 107
28000 -99999 8988 2163 -8 3112 130 2163 3112 12 28 -99999 411 -2 0 -36 -140 -11 101
25800 -99999 9505 2159 20 3179 171 2159 3179 11 27 -99999 410 5 -99999 -99999 -99999 -99999 93
25000 9710 9704 2163 -4 3214 143 2163 3214 12 28 -99999 411 -38 -26 18 -148 6 90
20000 11120 11120 2157 -10 3416 145 2157 3416 9 26 -99999 358 -4 0 7 -140 1 72
15000 12930 12928 2139 -28 3678 120 2139 3678 7 21 -99999 351 -12 12 14 -139 12 54
13700 -99999 13495 2123 -22 3746 138 2123 3747 6 17 -99999 344 -9 -99999 -99999 -99999 -99999 50
10700 -99999 15018 2089 -14 3956 156 2089 3956 4 11 -99999 331 -5 41 7 -113 -21 40
10000 15440 15431 2083 -11 4022 169 2083 4022 3 10 -99999 329 -5 44 34 -122 -25 37
9120 -99999 16001 2077 -15 4117 171 2077 4117 3 9 -99999 326 -6 63 -31 -136 36 34
7000 17600 17599 2053 -7 4390 200 2053 4390 2 7 -99999 317 -3 14 3 -79 8 26
5540 -99999 19002 2043 -99999 4670 -99999 2043 4670 2 6 -99999 313 -99999 18 -99999 -68 -99999 21

df_d_23022, header_d_23022 = IGRAUpperAir.request_data(datetime(1998,1,6,12), 'RSM00023022', derived=True )