Open English Wordnet
Adjectives
(a)unseasonablenot in keeping with (and usually undesirable for) the season“a sudden unseasonable blizzard”, “unseasonable bright blue weather in November”
(s)ill-timed, unseasonable, untimely, wrongbadly timed“an ill-timed intervention”, “you think my intrusion unseasonable”, “an untimely remark”, “it was the wrong moment for a joke”