Rain fly over tent, yes or no?

[AfricanFire]

Did my dry run putting up my tent and shade today. I have a small dome tent, with sealed mesh windows at the top (sealed for a prior burn and work great). I'll have a tarp shade over it. Previously I've always put the rain fly over the tent, but looking at my set-up now I can't see the need.

Am I just not thinking of something? Protected from dust -check. Protected from rain -check. Why would I want to put what is essentially a sail over my tent?

Thoughts?

[AntiM]

We do not use ours, it acts as a dust scoop.

[geospyder]

Might depend on how you sealed your mesh. My tent's mesh was sealed by another piece of tent fabric sewed over it. Problem is that the needle holes do leak water (never did seal them). Because of that I use my rain fly as a safety. Has worked great the few times we've had rain.