CDO

Hello,

I've tried searching through the forums and have read through the documentation but can't find the operator for this situation.

I have an .nc file of monthly avg temp values across 258 months. Each month has avg temps for 4 different depth levels.

E.g.
nrows = 1032
Jan,2015 5m 20 C
Jan,2015 15m 20C
Jan,2015 25m 19 C
Jan,2015 35m 18 C
Feb,2015 5m 17 C
etc.

I'd like to average the 4 depth levels for each month, so that I get:

nrows = 258
Jan,2015 19.25 C
Feb,2015 20 C
etc.

Perhaps I'm missing something obvious, but any help would be greatly appreciated.

Neil