Of course
The program will work for any number of days, but here it is used for just four days:
How many days to average? ? 4 Input rain for day number 1 ? 4.0 Input rain for day number 2 ? 2.0 Input rain for day number 3 ? 1.0 Input rain for day number 4 ? 5.0 The average rainfall is: 3 Press any key to continue