As suggested in a comment 3 years ago, this sounds like a snippet from Dean Kootz's From the Corner of His Eye. Here's the blurb.
Bartholomew Lampion is born on a day of tragedy and terror that will mark his family forever. All agree that his unusual eyes are the most beautiful they have ever seen. On this same day, a thousand miles away, a ruthless man learns that he has a mortal enemy named Bartholomew. He embarks on a relentless search to find this enemy, a search that will consume his life. And a girl is born from a brutal rape, her destiny mysteriously linked to Barty and the man who stalks him.
Barty has an insight into All they ways things are, which is another description for the Many Worlds form of Multiverse. Unfortunately like the original poster, I lent my copy to someone and didn't get it back so finding the exact quotes is proving challenging.
Barty uses this understanding of All the ways things are to walk where the rain isn't, and so stay dry in thunderstorm. He meets a girl of roughly the same age who shares some of this understanding. In a memorable scene they demonstrate this capability by walking around the garden hand-in-hand in a thunderstorm while staying dry. At the furthest point from the house, the children stop holding hands and the girl starts being rained on, her clothes changing colour as they get wet, while the boy remains unaffected.
Other things from this book that may jog your memory are a cast of many characters.
The view point switches mainly between Barty, a young boy who goes blind from childhood cancer, his eyes are removed.
Enoch Cain Jr the "bad guy" who in the opening chapters pushes his wife off a fire tower in the forest in order to become rich from the compensation.
Thomas Vanadium a detective and former priest who has a port-wine birthmark and his own understanding of All the ways.
And Jacob and Edom Isaacson, identical twins with monomaniacal fixations on disaster. Jacob is secretly an expert card mechanic and uses this skill to 'fix' a prophecy reading of Barty's future by a family friend. Despite his ability to stack the deck, the prophecy comes out differently warning of the danger Enoch poses to Barty.