Humidity can affect a maple wood floor as it will most other hardwood floorings. When the humidity is very high, the maple boards will fill with moisture and shift a little. This is not usually a huge issue as it will go back down when the humidity drops again, but over time, it could cause permanent damage.
If you live in a damp, humid part of the country, it is advised that you install a dehumidifier to soak up the excess moisture. The opposite goes for areas of the country where it is very dry. If you do live in an area with arid conditions, you will need to purchase a humidifier to keep the humidity level at peak condition.