Teachers certainly could get asked to work in July if a couple weeks of are lost in Spring, I think it's in the contract that there has to be so many instructional days (like if there were too many snow days, some extra days at the end of the year would have to get tacked on). Generally teachers get a 10 month salary (with Winter and Spring breaks paid) but summer is not. That being said, most teachers, if they have a continuing position, can have their pay spread out over 12 months.