Woodruff,South Carolina forecast. Look night temperature!
We have that weather in Finland in May. Have you some plants blooming? Willows?http://www.wunderground.com/US/SC/Woodruff.html
It seems good weather there. But this is a place of learning. When it is good weather, it is best to look inside what you have there. How many brood frames you have there.
If you have normal hive qnd they rise hives temperature for brooding, they spread all over the hive. That meand not that you give new space. When I start to bees big hive in spring with patty, it takes over a month that I may give another box.
I add first box under the brood area. So hive keeps it's heat and hive will enlarge downwards. You will se the miracle that hive does not need extra space for long time. They need to keep existing brood are warm. If you add 100% more sace, during first week warm just escape to upstairs and bees have difficulties to nurse brood area.
It depends so much how cold are nights and do you have rainy days.