This is the 12996th most frequent Swedish word.
säsongs
"Säsongs" is not an independent Swedish word but part of the word "säsongs-" meaning "seasonal" or "relating to a season."
Here, 'säsongens' is used as a possessive form meaning 'the season's', indicating the time period relevant to the event described.
Säsongens första snö föll i natt.
The season's first snow fell last night.
In this sentence, 'säsongens' again acts as a possessive modifier referring to tasks associated with the particular season.
Vi planerar för säsongens trädgårdsarbete.
We are planning for the season's gardening work.
Here, 'säsongens' modifies 'höjdpunkt,' specifying this peak as related to the season being referred to.