Synonyms for Unseasonable:

adj.

inappropriate (adjective)
untimely.
out of season (adjective)
untimely.

n.

inappropriate, harsh, humid, severe, sultry, inclement, threatening, muggy, fierce, unsuitable, raw, awkward. usual. unseasonable (noun)
inopportune, ill-timed, wrong, untimely.

Other synonyms:

inclement, humid, sultry, muggy. threatening. fierce. severe, harsh. raw. ill timed
ill-timed.
inadequate
unsuitable.
Other relevant words:
inclement, inappropriate, harsh, severe, raw, unsuitable, usual, awkward, fierce, inopportune, muggy, sultry, humid, threatening.

Usage examples for unseasonable

  1. The hour, as you say, is somewhat unseasonable and you will oblige me by letting me know to what I am indebted for the pleasure of this visit, as quickly as possible." – The Midnight Queen by May Agnes Fleming
  2. The hour is unseasonable and as to the motive- why, if Master Seadrift has got a little out of his course, no great harm can come of it, while the affair is in the hands of so discreet and amiable an officer as yourself." – The Water-Witch or, The Skimmer of the Seas by James Fenimore Cooper