When is Summertime in South America?

The rainy season is from Oct till May, so when does the sun shine?

South America is in the southern hemisphere, thus summer is generally November to March. South America is a continent with differences in climate and topography so different areas/countries will experience different areas. Which country are you asking about? When the sun shines depends on the country and obviously the weather.

In the tropical areas it's always hot. But there are two different seasons: the dry season and the rainy season. The dry season occurs between June and November, and the rainy season between December and May. Well, it's a rainy season, but it doesn't mean you won't have sunshine. It will be sunny most of the day, with rains in the end of the afternoon and beginning of the night.

In the subtropical and temperate areas, the summer lasts from December until March.

It's summertime there when it's wintertime in the US. It's always the opposite season.
When does the sun shine? Always! Even their wintertime is pretty warm and there's lots of sunshine.

The oppisite of America...