Where does winter go?

In the middle school world language classes we've been learning about the countries where Spanish is an official language. As part of a "Países hispanohablantes" Scavenger Hunt I asked the students to find a Spanish-speaking country where winter is from June to September (not just a place with cold summers!).

Can you think of one?

Here's a website I found helpful in explaining (the paragraph titled Opposite Sides — Opposite Seasons):

Seasons at timeanddate.com