The end of the rainy season this year seems to be later than usual.
「今年の梅雨明けは例年より遅いらしい」は英語で「The end of the rainy season this year seems to be later than usual.」という表現が良いと思います。
今年ーThis year
梅雨明けーEnd of the rainy season
例年ーAverage year・Normal・Usual
例年よりーThan normal・Than usual
遅いーLate
らしいーSeems to・Looks like・Appears
"It seems that the end of the rainy season this year is later than usual."
"The rainy season appears to be ending later than usual this year."
「今年の梅雨明けは例年より遅いそうです」という表現は英語では、"It seems that the end of the rainy season this year is later than usual." または "The rainy season appears to be ending later than usual this year." のように言うことができます。
以下はそれぞれの単語の意味です：
It seems that: ～のようだ
The end of the rainy season: 梅雨明け
This year: 今年
Is later than usual: 例年より遅い
アメリカ合衆国 
