I am installing two floors of hardwood for a customer in Northeast PA. It has been horribly rainy, damp and hot here the last few weeks.
The location is a summer/weekend home without air-conditioning...'
Upstairs - Mullican St. Andrews Oak Hardwood 3'x3/4
Downstairs (at grade) - Armstrong Westchester Collection 34-1/4x3/4 Engineered

My question is, the RH in the home has been hovering at 65%
I am running a dehumidifier to try to bring it down slightly. Flooring has been on site for a week. Not the customer informs me that next Thursday he's having a Ductless A/C system installed...
Im wondering what RH you'd suggest trying to achieve and acclimate the flooring to prior to installing to try to cover my bases between a low RH on weekends when the homeowner is there and running A/C... A higher RH during the week... And a dry, electrically heated house in the wintertime....

Thanks

shoot for the median and tell the customer without consistency in the environment the floor will move to equalize itself with the conditions that are present. Too humid its going to swell and too dry its going to shrink, how much really depends on his desire to save a buck on the hvac bill.