and yes. as they don't cover you nor most of the bike, you will get wet from rain.
rain that is sitting on the road, in puddles, full of salt and grime and oil and grease and the parts of small dead animals - yes, they are pretty effective at keeping that stuff off you and the bike.

but rain falling from the sky, no. you need one of these:



but even fenders, chain case, and an umbrella may prove ineffective!