I'm in Seattle so usually am dealing with moderate humidity, in super humid areas you can warm up your oven to the lowest possible setting, once warmed up turn it off and put the mint directly on the oven racks if you wish or on cooky trays. The easiest would be to take out the oven racks first, warm up the oven and turn it off. Have it open just long enough to reinsert the trays and then ignore until the next day.