Hi Hannah, After looking into it some more I noticed two things, 1) GDPOINT requires SCALE = 0 to disable automatic scaling, 2) a grid scaling routine is called each time, no matter if the grid needs interpolation. Therefore the value reported by GDPOINT will always be slightly different than the actual point value as shown in GDINFO. I'm working to fix this. Michael Ticket Details =================== Ticket ID: CEW-233266 Department: Support GEMPAK Priority: Normal Status: Open