This is the 4576th most frequent Japanese word.
強まる
"To become stronger" or "to intensify."
Here, "強まる" describes the increasing intensity of the cold, showing environmental changes or escalation.
寒波が続き、寒さがさらに強まっています。
The cold wave continues, and the chill is intensifying.
The word "強まる" is used here to describe the wind increasing in strength, showing its capability to intensify.
風が強まると、外に出るのは危険になります。
When the wind intensifies, going outside becomes dangerous.
"強まる" is used in this sentence to depict a person's will becoming stronger, indicating internal strengthening or fortification.