Error when averaging empty & non empty cells

Hi

I have been helped on another post with a problem averaging only unique figures from a column. (I've only started this new one so new viewers don't have to wade through all my posts in the old one)

I am using the array formula =AVERAGE(IF(FREQUENCY(A2:A31,A2:A31),A2:A31)) which has worked brilliantly but only if there are less than two blank cells in the list.

My problem is that I will be starting each month with a blank list and adding to it each day so the formula as is will only work on the penultimate day of the month.

Could someone please help? I am using Excel 2013.

Thank you.