high season
US /ˈhaɪ ˌsiː.zən/
UK /ˈhaɪ ˌsiː.zən/

1.
temporada alta
the time of year when a particular holiday or tourist destination is most popular and prices are highest
:
•
Traveling during the high season can be very expensive.
Viajar durante la temporada alta puede ser muy caro.
•
The hotel is fully booked for the entire high season.
El hotel está completamente reservado para toda la temporada alta.