The sentences that contain a comma splice are:
- 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.
Each of these sentences incorrectly joins two independent clauses with just a comma. The second sentence ("He heard it was going to rain, but now the weather looks fine.") does not contain a comma splice because it properly connects the two independent clauses with a coordinating conjunction ("but"). The last sentence ("It is a perfect day for playing baseball.") also does not contain a comma splice as it consists of a single independent clause.