South Africa is a great country to volunteer in. It is relatively safe, has great nature to explore and of course is English-spoken. The free and open platform kindmankind.net has a listing for Volunteering Opportunities in South Africa: http://kindmankind.net/map?region=southernafrica. Related
One of the most appealing African destinations for volunteering is Cape Verde (official name in Portuguese: Cabo Verde). The group of ten volcanic islands off the coast of West Africa measures 4000 square kilometers and are inhabited by about half a million people. Cape Verde is independent from Portugal since 1975.
Since its latitude is similar to Central America, the temperature is above 20 degrees centigrade year-round.
Cape Verde is a Christian country, with 85% of the population officially Roman-Catholic in 2007.
Tourism is one of the most important sources of income for Cape Verde, and it is considered a very safe country. Interestingly, it gets the highest grade (on a par with Western European countries) from leading rating NGO Freedom House.
Although you can read stories on sites like Trip Advisor about people being robbed, but these are really the exception if you consider the annual amount of tourists visiting Cabo Verde is 500,000 (most of them are English).
A somewhat justified concern is pick-pocketing. The official Cape Verde information website warns for bands of mostly Nigerian or Senegalese men snatching your possessions in Praia, but also in Santa Maria, or the islands of Sal or Boa Vista. But if you booked your vacation in one of the new Club Hotels (like Riu Karamboa or Riu Funana/Garopa, both islands upon themselves with close to 1,000 rooms) you won’t have to worry about anything.
Cape Verde is still dependent on foreign aid (the minimum wage is about 100 Euros). There are plenty of organizations that offer volunteer stays in Cabo Verde.