I have a cousin that sells by tye roadside and when a heavy downpour occurs, she comes back home saying that the rain spoiled market that day. It is a good place to start but one shouldn't settle to keep selling on the roadside after a period of time.
actually even during the rainy seasons it still works because there are still a lot of people that do their business by the roadside and it is a success for them all the time even when the rain falls and they have umbrellas which ones that they using people that passersby can stop there to take shelter then patronize them.