I do believe that in circumstances involving extreme weather conditions that school classes should be cancelled. Severe weather events can often be more dangerous than they appear and proper precautions need to be taken. These situations need to be taken seriously, and the safety and health of students should be put above anything else.
When weather conditions create hazardous road conditions, schools should suspend classes for the safety of students, personnel and parents. When impending dangerous wind conditions threaten to strike during hours that impact classes, officials should also suspend classes. In all cases, the preservation of human lives remains the ultimate deciding factor regarding suspending school classes due to weather conditions. I always trust local officials to err on the side of caution.
Yes, classes should be suspended due to weather under some circumstances. This is especially true when the roads are treacherous (icy, snow covered, sleet) and if there are high winds likely to result in downed trees or other debris that might cause accidents or knock out traffic lights. If it's dangerous to be on the roads, classes should be cancelled.
Yes, weather is a good reason to cancel classes. When there is inclement weather, it becomes dangerous for students and teachers to travel. Suspending classes for weather is a good thing because it ensures the safety of all the people involved in the classes. There is no reason to have a class if the weather does not permit.
It depends on the type of weather and the weather conditions whether or not schools should be closed. For example, if it simply rains a lot, where the the weather is unfavorable, but doesn't necessarily prevent a majority of the students or staff from making it to school, then school shouldn't be closed. However, if there's a hurricane with 100 mph winds, where it is very likely that any students or staff attempting to get to school could be injured, then yes, school should be closed for however long the harmful weather lasts.