Beginner roller skating
On Wet Ground, the Puddle Isn't the Problem. The Smooth Bit Is.
Beginners watch the rain. Experienced skaters watch the surface. Water on rough tarmac grips more or less fine, and a puddle on it is a non-event; a painted line, a metal plate or polished stone will go from grippy to lethal with almost no water at all. Nothing sticks to your wheels either, so the second you're back on rough ground you have grip again. The question was never how wet it is. It's what you're rolling on.
Beginners watch the rain. Experienced skaters watch the surface — and the difference between them is a single fact: it is the texture of the ground that makes it slippery, far more than the amount of water on it.
Water on rough tarmac grips more or less fine. A puddle sitting on rough tarmac is close to a non-event. A painted road marking, a metal plate or a polished stone slab goes from grippy to lethal with almost no water at all, because there was never any texture there to start with.
There is a second half to this that nobody mentions, and it is reassuring: water does not stick to your wheels. The moment you are back on rough ground you have grip again. You are not carrying the puddle with you.
So the question was never how wet it is out there. It is what you are about to roll over.
Keep going: this is one section of the full Roller Skating for Beginners guide — sizing, gear, stopping, and where to skate, in one page.