This is the 3353rd most frequent Japanese word.
春季
"春季" means "spring season" in English.
The word 春季 refers to the season of spring in temporal terms.
春季には花が咲き始めます。
In spring, flowers start to bloom.
Here, 春季 denotes the time period when the tournament takes place, indicating it occurs during spring.
春季大会が来週から始まります。
The spring tournament starts next week.
In this sentence, 春季 is used to indicate the spring season generally, associated with its typical weather conditions.