"Winters are cold and long here."

[NinaOBel]

Zimy jsou studené a dlouhé tady - error? Why 'tu' and not 'tady'?

[VladaFu]

Tu and tady is the same, but the word order is awkward.

Although I can imagine it if you stress "tady" strongly. Still hard to imagine the context for such a sentence.

[NinaOBel]

Can Duo say about wrong order in error message?

[VladaFu]

I think it can't.

[imdumby]

Is zima not a word for cold?

[VladaFu]

It is, but it is a noun and it can be used in adverbial constructions. We need an adjective here, "studený" or "chladný" are both possible.