I think cdo is best suited to do JAS and monthly
Cdo yearmean - selmon, 6/8 input file output file
Something like that check cdo documentationOn Aug 7, 2016 2:58 PM, "Nitin Patil" <nitinpatil85@xxxxxxxxx> wrote:Dear Ferret users,I have 40 yrs of data set from Jan-1971 to Dec-2010 but I have to only use JJAS and one month June from 40 yrs.Any idea how to select and take mean for this?--Regards,Nitin Patil