Formal:
* Quand la pluie cessera: This is the most literal translation and is the most formal option.
* Lorsqu'il ne pleuvra plus: This is another formal option, using "lorsque" to emphasize the moment the rain stops.
Informal:
* Quand la pluie arrêtera: This is a more casual way of saying it.
* Quand il ne pleuvra plus: This is also a more informal option, but it's still grammatically correct.
More specific:
You can also be more specific about the type of rain or the duration of the rain:
* Quand l'averse sera passée: This means "when the downpour is over."
* Quand il ne pleuvra plus du tout: This means "when it stops raining completely."
* Quand la pluie s'arrêtera pour de bon: This means "when the rain stops for good."
The best way to say it depends on the specific context and the level of formality you want to achieve.