SEASONALLY

seasonally

(adverb) depending on the season; “prices are seasonally adjusted”

Source: WordNet® 3.1

Etymology

Adverb

seasonally (comparative more seasonally, superlative most seasonally)

Occurring every season.

Occurring only in season.

Source: Wiktionary

SEASONAL

Sea"son*al, a.

Definition: Of or pertaining to the seasons. Seasonal dimorphism (Zoöl.), the condition of having two distinct varieties which appear at different seasons, as certain species of butterflies in which the spring brood differs from the summer or autumnal brood.

Source: Webster’s Unabridged Dictionary 1913 Edition