At what temperature does a school have to close in the US?

There's no single temperature at which schools in the US are legally required to close. The decision to close a school due to weather (heat or cold) is made at the local level and depends on many factors, including:

* The specific school district's policies: Each district sets its own guidelines.

* The age of the students: Younger children are more vulnerable to extreme temperatures.

* The school building's infrastructure: Some buildings are better insulated and have better heating/cooling systems than others.

* The availability of transportation: Bus routes may be unsafe or impossible in extreme weather.

* Local weather conditions: It's not just the temperature but also wind chill, humidity, and the potential for other weather events (like ice or snow) that factor into the decision.

In short, there's no magic number. Schools will often close due to extreme heat or cold, but the exact temperature threshold varies widely.