Does my cat have asthma

Every night my cat starts coughing approximately between 10:30pm and
11:30pm. It's short in durating, but it's getting worse in the respect
that it started out like a cough. The last 2 nights, it sounds like an
asthma attack. He's fine during the day - doesn't cough at all. I had
him checked by the vet for worms, but I'm not sure if the vet did a
lungworm test. If he had lungworms, wouldn't he cough all throughout
the day? Same if he had bronchitis, wouldn'e he cough all day? Because
it's only once and approximately the same time each day, I'm leaning
to thinking it's asthma. Your thoughts?