[tpurves]

Weather can be a problem for airships. Their max airspeed can be much less than what's needed to maintain station in a strong wind. The US navy also gave up on (manned) airships in the 20s after big storms would bring them down with loss of life.

If you don't mind that they get blown downwind sometimes, or that sometimes you have to ground them, or you just use them mostly during good weather or good seasons, or if they crash and you only lose equipment not people on board, then blimps can be viable.

Some parts of Africa might not even see a lot of seriously adverse weather.