I hunted last week from a double bull during a full day of rain, sleet, hail, wind, and snow...and stayed dry. I even stayed warm with the occasional lighting of a can of sterno.
BUT, popups are problems in that deer are very wary of something new in their territory even when covered with brush (I do not care what the DB folks say about that). I observed long stares from the deer at 50-100 yards and they failed to come closer. I hear they work well in wide open country, but I will avoid them in forested terrain (that is, if the weather is half way decent).