I dove down a high jump DnD rabbit hole

So basically, if you have some sort of magic item that makes your walking speed at least 47 feet, a potion/belt of storm giant strength, and the spell "jump," you can jump straight up (with a slight running start) and grab a ledge 45 feet above the ground. This assumes that the spell jump triples high jump, which it does to the best of my knowledge, and that your character is the average 6 feet.

Thats a take off velocity of 58.8 feet per second, and you would clear it in 0.5 seconds.