How to calculate average of one column, based on the values on another column

Hey :-)

This is Sadra. I'm working on my master thesis on Remote Sensing and urban Heat Islands. I need a help with calculating average values in excel, and I appreciate any help of you.
So I have two columns of data, named "Grid" and "Temperature" (snapshot included below):

Capture.JPG

I would like to calculate the average of column B (Temperature), BUT based on the length of the values in Column A (Grid). In other words, I want the average of B2:B9, B10:B12, B13:B15 and so on.


Many thanks in advance for your help,
Best Regards,
SAdra

why cant you use the =AVERAGE(B2:B9) etc. function?

Originally Posted by Legend Rubber

why cant you use the =AVERAGE(B2:B9) etc. function?

I can, but it will take me a month to calculate it as I have 24000 rows to calculate :-D
And beside that as you can see in the snapshot, each time the amount of fields on B varies based on the values on A. Sometime the average is for 3 rows, some times for 7, and that's annoying!
I hope you understood what I'm looking for

Cheers,
Sadra

Originally Posted by daddylonglegs

Try AVERAGEIF function

List all your grid numbers in D2 down, e.g. 0, 1, 2, 3 etc. then in E2 use

=AVERAGEIF(A:A,D2,B:B)

copy formula down

Thank You Very Much Dude!! I appreciate your help

Cheers,
Sadra