In about a month, the annual school budget season will come to an end with voting on 2011-12 school year spending plans.

That’s a venerable rite of spring across the North Shore and, like the season, the outlook can be bright and sunny or dark and stormy.

It’s an odd, and some say antiquated, process. Nobody votes on federal, state, county, town or village budgets and, in fact, no one really votes on a school budget. Not the entire package, anyway.

As is the case with municipal budgets, school spending generally falls into two basic categories, mandatory and discretionary.

Mandatory spending includes salaries, transportation, heating and lighting. By far, that’s the bulk of the budget. In that regard, school spending is exactly the same as that of government at various levels.

Even if there isn’t a single “yes” vote cast, paychecks still must be issued, buses gassed up and heating oil delivered. You can toggle the “no” lever until this year’s graduating seniors retire, but that will have a relatively small impact on the bottom line: in this case, school property taxes, which account for about two-thirds of the average property tax bill mailed out by the town.

So exactly what is the purpose of a school budget vote? It’s evolved into a referendum on a school system in general and, at times, the administration, including the board of education.

Because this is the only opportunity we have for a direct — albeit quite limited — say on taxing and spending, some of us automatically vote no. In recent weeks, teacher salaries have been in the cross hairs. Yes, they fall under mandatory costs, but some believe their no vote provides the administration with a guide on how to proceed the next time contract negotiations begin.

There are those who automatically vote yes, no matter what, because they are unconditional supporters of their schools. And then there’s the rest of the voters, who may vote one way or another, depending on their sense of things: Are the students performing well academically? Is spending reasonable and wise or out of control?

No time is a good time to hike property taxes, and yet that seems to be on the horizon to varying degrees. In the weeks left before the May 17 voting, residents should take the time to examine what their school districts have put on the ballot. Emotional responses are understandable but not at all helpful.

If you’re voting to send a message, be sure you know what that message is and how it might affect your wallet, your neighbor’s wallet and the kind of education we’re giving our kids.