involve auto fill for cells...

what a i want to do take an average of a group of cells, then autofill for the next set of cells.
awful explanation i know. example:

G1=AVERAGE(E2:E25)
G2=AVERAGE(E26:E49)
G3=AVERAGE(E49:E72)

and so on...however when i autofill it just starts at the next cell after E2, or E26 (E3:E26 or E27:50)

if its still a bad example ill try to explain further

Use VLOOKUP

what im trying to do is get the average temperature for each day.
im given the temperature at each hour, for 365 days