Answer:
It's invalid
Explanation:
What has been attempted i the question is inductive generalization.
Now, to say July is summer is okay.
But to say if it's not July, it's not summer is drawing a generalization that doesn't necessarily apply because it doesn't take into account other factors which are not stated.
This is because July may not be the only month in the summer. It could just be part of the summer months.
Therefore, it's invalid to claim if it’s not July therefore it’s not summer.