"Is it cold in December and January?"

Translation: Decemberben és januárban hideg van?

[Freddioso]

So am I right in thinking that adjectives require 'van' in impersonal constructions? So to say 'it's cold' you can't just say 'hideg', it has to be 'hideg van'?

[GregWood15]

Would it be appropriate to use definite articles here as it sounds like a general statement?