Answer: autumnal

AnswerCrossword Clue
AUTUMNALLike October
AUTUMNALOf frost, red leaves, etc.
AUTUMNALFall-like
autumnalthe season between summer and winter comprising in the northern hemisphere usually the months of September, October, and November or as reckoned astronomically extending from the September equinox to the December solstice called also fall
autumnalperiod of maturity or incipient decline in the autumn of life
autumnalpertaining to autumn (a season of the year)