Hunters usually remain indoors during any heavy rain. To the deer, it's just another wet day. They are used to it and live through all sorts of weather their entire life. Yes, the deer will usually bed down during a heavy rain and most hunters know where to look. Most times it's under heavy cover, especially pines, that offer security and relief from nasty weather.

I have hunted in heavy rain many times and have killed a few decent bucks. Most times, the bedded deer will either move and give me a chance to pick up their motion or they will rise suddenly to check out what they thought they heard. Just because we think it's a miserable day, the deer may not necessarily agree. Besides, that's why they make rain gear.