I saw a Youtube video which described spot selection and orientation. Like a tent, it takes some forethought to keep from getting too wet.

Around here the storms mostly come from the west, so you would want something to shield the wind from the west.

Then you point your feet 45 degrees off from into the wind.

If I get hammock, I'll probably car camp with it when I'm expecting rain and have a tent set up just in case. But I can guarantee it won't ever rain until I go away from the car.