Can the word hivernal be used by itself and still have meaning. Or would it only ever be used in a sentence? Would it look odd to a French-speaker to be seen by itself?
Is an adjective linked to winter, and yes we can use it alone, see the edit. Most of time you will see
Wich means "Temperature from Winter"
Edit : I totally forgot about the use of an adjective in interrogatives or exclamatives ways. Thanks jlliagre and aCOSwt for the reminder !