(1)時機の悪い
(2)季節に合わせてでない（そして、大抵好ましくない）
(3)badly timed
(4)not in keeping with (and usually undesirable for) the season; "a sudden unseasonable blizzard"; "unseasonable bright blue weather in November"
さらに詳しく
(1)あいにく
(2)by bad luck; "unfortunately it rained all day"; "alas, I cannot stay"
