To avoid these two risks (storm and attack), I imagine it'd have to be at an altitude above weather currents and beyond shooting range... or be able to stabilize during a storm and be bulletproof.
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.
What kind of defenses to you think the blimps will have to defend against these strikes? Some sort of armor plating on the underside would seem to be the minimum. Hopefully they'll be equipped with some offensive capabilities as well to combat and dissuade guerrilla and terrorist acts.
Or would it make more sense to just use expendable blimps, like a $10 balloon and a $20 router?
Um ... Google drones are the last thing we need. Enough problems with the military ones already.
Of course the warlords who might actually control some parts of these countries wouldn't have that ability nor would they care about shooting it down.