CDO

Hi Shane!

you might try the yearmax operators. See here or check

cdo -h yearmax

Thanks Ralf for suggestion,

I went through the operators as per your suggestion and I found the operator below
but I am struggling to run it on the command line, or perhaps do you know how to run it?

Yearly maximum
For every adjacent sequence t_1,...,t_n of timesteps of the same year it is:
o(t,x) = max{i(t′,x),t1 < t′≤ tn}

Frist of all, you can prepend it to any of your calls like

 cdo  -outputtab,date,name,value,lat -yearmax <ifile>

BUT: yearmax only gives a single timestep. hence it cannot provide multiple date/time values for possible different dates for different grid points. With this technique you can only get the max values and their location, bot not the datetimes.

is your input horizontally distributed or only a single point?

To write the date, value and lat (only?) for the maximum value of your lonlat data for each timestep to an output file you can do the following.

Example 'infile.nc' with variable 'tas'

cdo -s -outputtab,date,name,value,lat \
       -selname,tas_max \
       -expr,'tas_max=(tas==fldmax(tas))? tas : tas/0' \
       -yearmax \
       -selyear,2020/2099 infile.nc | grep -v 1e+20 > outputtab_date_name_value_lat.txt