We have a few dozen boxes of laminate flooring purchased a few weeks ago (Harmonics with Uniclic, if anyone's interested). These have been stored in an unfinished basement in central Minnesota, and are destined to be installed on the first floor. We generally don't use the air-conditioner in summer, unless humidity levels are uncomfortable. Effectively, first floor and basement are mostly similar in local comfort conditions.
In this scenario, how long should we let the laminate planks acclimatize to the first-floor weather conditions, considering that the basement isn't severely different in temperament?
Would just a few hours do, or should we really let the planks sit idle for a couple of days to make sure there won't be any future usage problems?
My intent in asking this question is to roughly figure out what sorts of temperature + RH tolerances are built in to laminate flooring, and how critical differences of a few degrees in temperature or a few percentage points in relative humidity are.
Edit: (hopefully) related questions: Will installing laminate floors in winter show any different results from a summer installation? Will I see any shrinkage around the baseboards, for example? Or will heavy furniture cause gaps between installed planks in winter?