How can a school be closed?

Answer 1

Schools are allowed to close if school officials believe that conditions are hazardous, and rain is one of many potentially hazardous conditions... for instance, if the school is in an area where a flash flood could occur, or if a significant portion of the school's students would have to travel through such an area to get from their home to the school.

Barring weird local ordinances, though, it would be unusual for there to be a specific amount of rain that would legally require a school to close.

At least in the US schools are required by the state to hold classes a certain minimum number of days per year, so officials are generally reluctant to close school unless they believe there is a real likelihood of danger since doing so means they may have to extend the school year ... never popular, since that conflicts with many families' vacation plans (and often, for teachers and older students, summer jobs).

Answer 2

In areas where there is wintery weather, schools sometimes close because of snow and ice making road conditions slick and hazardous.

Schools also may close for serious outbreaks of viral infections so that they do not spread from one person to another.

Natural disasters and other emergencies can also cause schools to be closed.