Light to moderate rain has very little effect on deer and they go about their business in the same manner as they would on a sunny day.
Heavy rains or thunderstorms will cause deer to bed down in a sheltered area of some kind. Any high winds, rain or not, will also discourage their movement.
Since light rain doesn’t alter a deer’s activity, this time can be very rewarding for you. Those who love hunting during this time have taken their biggest bucks during a light rain. One reason is there are fewer hunters to spook the deer since they went in out of the rain.
Wet ground and rain on the leaves also makes it easier for you to move around on the ground and get into position undetected.
Rain also helps mask human scent. All this put together gives a buck confidence to move around on rainy days and gives you a great chance to take a rain deer.