Answer:
The object to the preposition in the sentence We avoid hiking in the summertime is summertime.
Step-by-step explanation:
The preposition shows the relationship between its object and another word in the clause. The object to the preposition is a noun that comes after a preposition to complete a phrase. In this case, the preposition in shows the relationship between hiking and summertime, being summertime the object to the preposition in.