Really it depends on the type of white widow you have. Ive grown 5 types of clones called white widow. All very similar to each other except "elephant widow" that was a beast.
You should be ok outdoors. Humid in veg outdoors isnt bad. And if the weather dries out in second half of flower thats more important.
Theres many preventative measures and practices in growing you can do to prevent mold. And many preventative products available as well.
As far as prone to bud rot i feel only a few plants out of thousands ive grown are just prone to bud rot, that kinda melt like wet toilet paper. White rhino was one of those it did not like rain at all, not one drop. Otherwise its usually caterpillars from moths that get colas in the end with bud rot. Widow colas are fat and easy for a caterpillar to tunnel deep to the center, and have a picnic.