Funny you say that. For some reason I had in my mind that 'winter' moves around the earth. But thinking about it, it doesn't work. It's just hemispherical.
Technically not quite hemispherical in that the tropics don't experience seasons either way.
Or how my uncle put it, they have "rainy season" and "not so rainy season", the difference being it rains every day at around 1pm in rainy season and "only" every second or third day in "not so rainy season", with neither being "summer". More like "summer & winter" vs "autumn & spring" or vice versa.