Right now in summer in NY area. Should I have a humidifier going during the day at 55% setting to keep humidity at a constant level or should I also use the AC to lower the temperature as well ?

I'll be installing 3/4" red oak and I want to make sure that the environment is in a normal condition so that gaps are minimized during winter time, etc.

Any other help/suggestions is appreciated.

thanks.

I believe that your geographic area should have the same general climate as here in southern Ontario. There should be no need for a humidifier in the summer, you should actually need a dehumidifier, or utilize your AC to reduce humidity.

Thanks, Dennis.
I meant to say dehumidifier. Is it enough to have it at say 55% without the ac ?

I think you should try to achieve 45% since that would be an easier target to maintain in the winter. The goal is to minimize the swing in humidity levels from season to season. Even so, the max range would be (for most manufacturers) 35% to 55%.