Ignore the last answer which wasn't the question you asked:)

This hopefilly is

=AVERAGE(IF((MONTH(P5:P200)=1)*ISNUMBER(P5:P200),( O5:O200),""))

This is an array so commit with CTRL+Shift+Enter Not by simply pressing enter.

Mike

"Mike H" wrote:

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