I did some checking, and I believe it is mostly the server. There is a poorly documented way to improve the speed at the cost of using more memory. add the string "[cache]" to the front of your url when you pass it to nc_open. For example "http:..." becomes "[cache]http:..." =Dennis Heimbigner Unidata Ticket Details =================== Ticket ID: SHE-717035 Department: Support netCDF Priority: Normal Status: Open