low season

Từ điển Oxford Advanced Learner 8th

ˈlow season [low season] BrE NAmE (also ˈoff season) noun uncountable, singular (especially BrE)
the time of year when a hotel or tourist area receives fewest visitors
•There is nothing more depressing than a seaside town in (the) low season.
Opp: ↑high season
See also: ↑off season