Couple of things, teachers get paid for the 190 (or so, a couple systems have a day or two more) they work. Those days can be anywhere between July 1 and June 30, the fiscal year. So yes, teachers get "paid" for snow days. But when they're made up in June they're "unpaid", you're just making up the day you missed and were paid for back in January.
Also, and we've had this discussion before, teachers in most systems in MD have the choice to get paid 22 times per year or 26 times. The 22 times is during the school year and ends with the last pay in June. The 26 pay option is year round pay. The check is smaller each time but the additional 4 pays (the summer) is deferred compensation for the 190 days, or so, of the school year.
As to contracts. Contracts are binding in MD except for teachers. When teachers were given the right to collective bargaining back in the 1970s one of the components was that the County or School Board could declare a fiscal emergency and void the salary, and in certain circumstances the benefits, agreed to in the contract with the teacher's Association (not union, can't use that word in MD as it relates to teachers). That's why school boards are able to not honor contracts. If the funding doesn't come from the County Commissioners it's not there for the School Board. That was done because in MD school boards don't have taxing authority, as they do in states like PA, and could agree to outrageous terms that the Commissioners would have to find funding for.
That's the short course, I haven't even gone into MoE (Maintenance of Effort).