This is the 1852nd most frequent Japanese word.
晴れ
Sunny or clear weather.
In this sentence, '晴れ' is used as a noun to describe the weather being sunny or clear skies.
今日は晴れです。
Today is sunny.
Here, '晴れる' is used as a verb meaning 'to become clear' or 'to clear up' regarding the sky or weather.
空が晴れてきた。
The sky has cleared up.
This sentence uses '晴れの日' to refer to 'sunny days,' explicitly combining '晴れ' with '日' to specify days with clear weather.