Try,

=SUMPRODUCT(--(ISNUMBER(P5:P200)),--(MONTH(P5:P200)=1),O5:O200)

Mike

"sarahg" wrote:

Hi

I have a list of numerical values (P5:P200) in O5:O200 is a corresponding
date as to when the values were recorded. How can I calculate an average of
values collected within a specific month.

Thanks