There are some places in the world that are sunny almost all the time so if you want to see an eclipse those are the places you want to be. There are also some places that are cloudy almost the entire time, so you should chose somewhere else as your eclipse site (if you can)!
Jay Anderson is acknowledged by eclipse observers as the "go to" weather expert for advice on this topic. He has just produced his latest Cloud Map, giving a general overview of cloudiness anywhere in the world on https://eclipsophile.com/global-cloud/
It also helps to do some work on "micro-climates" to get into the dine detail, but if you are planning to travel a long distance to see an eclipse, it would be good to know you have a good chance of a clear sky!