This means, "What are the months of winter?" In general, "Qué" means "what" and "Cuál" (singular) or "Cuáles" (plural) means "which"--but in a case like this you would use "what" in English but "cuál" in Spanish.
Estan= to be
meses = months anos = years
Months
The Months
cuales is the plural of "which", so the translation would be "which ones".
it means the "the months of the year"
He/she write the months.
12 months
they are in
They are proud.
Qué meses tiene el otoño? : What months is it autumn/fall?