rain or shine
Homemaker from Southern desert, CA
I purchased a used outdoor table set and the seller did not include the deep seat cushions. I made my own as I am a seamstress but this time investment would be useless if the covers were damaged from the rain and sun.
I found these chair covers to be very snug and perfect fitting. They have elastic around part of the bottom so they hug the legs of the chair. We had a huge wind storm and they didn't move at all. There are also some ties to go around the legs but we didn't have them tied during the wind and they stayed put.
We then had rain the same week. Not heavy down pour like we get sometimes, but enough to show me how they would handle water. I saw the water bead on the surface. I took it off after the rain stopped to see the inside and underneath and no water signs showed on the inner. The cushions were completely dry.
When we go out to sit, we can easily take the covers off with the two handles attached. It does take a bit of maneuvering to get it off (and back on) because the elastic around the bottom is secure and tight. This is something that I would expect though as I would need the covers to be secure and tight to protect my chairs.
So with a tad bit of work and adjusting the covers are slipped on and off when needed and you know they are there to do their job.