Answer:
Raj wants to get tickets for the baseball game, he knows it might rain though.
The skies are blue, there is not a cloud in the sky.
Raj knows he will regret it, he just can’t stay inside on a day this nice.
Explanation:
A comma splice occurs when two independent clauses which can stand on their own are separated by a comma. Instead, they should be joined by semicolon, by a comma and a coordinating conjunction, or by dividing the clauses into two separate sentences. Thus, the revised sentences are the following:
Raj wants to get tickets for the baseball game. He knows it might rain though.
The skies are blue; there is not a cloud in the sky.
Raj knows he will regret it, but he just can’t stay inside on a day this nice.