Syllable division and stress derived from spelling — this word is not in the pronouncing dictionary, so no phonetic transcription is shown rather than a guessed one.
unseasonable is an adjective meaning "not in keeping with (and usually undesirable for) the season". It carries 2 recorded senses.
not in keeping with (and usually undesirable for) the season
“a sudden unseasonable blizzard”
“unseasonable bright blue weather in November”
Definitions, synonyms and semantic relations for unseasonable come from Princeton University’s WordNet. Commonness is measured against a corpus of everyday English. Full sources and licences.