Finding Averages in a set of cells based on values in part of a set of different cells

NOTE: Sheet is attached

I have an excel sheet that contains one column ("Email Send Date") with cells that contain both a date and time. For example, "8/18/2016 6:00:00 AM". There are a bunch of other columns with different percentages for a variety of KPIs.

My question is how can I find averages for these different rates (for example, the unique open rate) based on the time in the "Email Send Date" cell (ex: 6:00:00 AM, 7:00:00 AM, etc.)? Or do I have to separate the date and time?

Thanks in advance.