Are you cleaning up the poo with an enzyme cleaner? If they can smell the scent, they'll want to go there again. The rain might have something to do with it, if you're not taking her out in it. I always take my pups out to play in the rain so that they don't have an issue with it later. Some dogs (like my DH's AmBull) will hold it until she's ready to pop because she won't leave the house in the rain. Silly girl, lol.
We clean it with an all purpose cleaner. I will have to get an enzyme one after work to try. We let her out in the back yard but don't normally play outside when it rains so that could be the problem. I've told my bf to keep her tethered to him for now so any accidents can hopefully be prevented.