We moved to a small town in Ohio 6 yrs ago. The flag in our local cemetary has been at half staff for all those years. Like you, I’ve asked and no one seems to have an answer.
When we grew up half staff actually MEANT something.
Perhaps it is to honor one of your state’s fallen service men or women.
In our state of Michigan, whenever a person from our state is killed in combat, the flag is lowered to half staff. The Governor orders the flag moved. It is on our state’s website listed as “Half-Staff Flag Alerts.” It is law put into effect in our state in 2006. Given the number of wars/conflicts/battles going on maybe it’s not so unusual for the flags to seem to be lowered so often.