How can I match data fields in two columns on one file with those in another file?

Hello,

I have two sheets named as "Atmos" and "Surface" in a single Excel file (attached). What I'd like to do is to copy the data in "Surface Condition" and "Surface Temperature" columns in "Surface" sheet and paste them into the columns in "Atmos" only when their "Station_Name" AND "Observation Time" match, and write "N/A" when there is no matching record. The actual dataset contains nearly half million rows to match and copy from..

I am not sure if there is a simpler way to do this without having to write a VBA code... Your help on this would be highly appreciated.

Atmos.JPGsurface.JPG