Answer:
Step-by-step explanation:
Suppose you want to know how many miles a tire gets before it must be replaced.
Suppose further that you live in a place where the roads are not very good. You would be quite concerned about how you were going to take road conditions into account.
Is rain different from snow? Will the tire get more miles in rain or snow?
Does the tire respond differently after the rain has stopped? It likely will, but how differently.
What about getting stuck especially if an alligator is the only thing looking at you being stuck and he has lunch written all over his face. Is the tire able to get you out?
All of these factors will be very important because no two seasons are alike and one July (say) of one year is not the same as another July in a different year. There has to be a way of determining what the numbers mean.