If you are worried about them getting wet you could just throw a lean-to or an a frame over the plant and put a tarp over it. A bit of rain isnt anything thats gonna end the world but its when youve got consistent days that are damp and rainy. Its not so much in early flower but in the end that youll see mold/fungus issues cropping up if conditions are conducive. Some strains are also just uber mold resistant, others are the complete opposite. Basically in summation, covering from the direct rain is the safest approach but if you dont youre still in the clear. Good luck brother, best of luck man