- not usual for or appropriate to the season: unseasonable heat
- not in season: unseasonable seafood
- coming, said, etc. at the wrong time; untimely; inopportune
- Not suitable to or appropriate for the season.
- Not characteristic of the time of year: unseasonable weather.
- Poorly timed; inopportune.
(comparative more unseasonable, superlative most unseasonable)
- Not in accordance with the season.
- The snow in April was unseasonable.