Weather percentage risks? Please explain?

[MarianForrester]

Can anyone explain these to me, please?

For example, a day is forecast to have a 40% chance of rain. Then each individual hour has its own percentage chance of rain.

And sometimes a day will be forecast to be wet, with said 40 per cent chance of rain, but I don't understand how that means it is more likely to rain than not?

If someone could explain in simple terms I would be most grateful.

[OhYouBadBadKitten]

Sorry marrian, didn't see this. Can I ask where you are getting your forecasts from? It will help me explain a bit more.