Western Africa in July?

[Wheelie]

I am looking into riding a scooter from Tanger to Dakar, maybe even to Gambia in July.

I've read that temperatures and rain in Western Africa can be ferocious. However, the sources generalise about an area far greater than the US or Europe, leading me to think that different regions are likely to be vastly different, just as the differnece between east-west-north-south are very different in both Europe and the US. Most sources advice against Western Africa during the summer. I don't know, but I have come to believe that the temperatures and rain really doesn't prove to be an issue unless you go further south than Dakar or if you go east, away from the coast. Any comments?

What I wonder is how would the conditions be on the route from Tanger to Dakar? I believe most of the stretch is close to the coast. Comments?

Temperatures, rain, humidity? Morocco? Western Sahara? Mauritania? Senegal? How about Banjul Dakar? Comments?