My take on it is based on my very limited knowledge of physics and HVAC. Winter in the Northeast are our driest time of the year, yes we can get 3' of wet snow, but the relative humidity is very low. Think dry tundra, is really a winter desert.. Now if the temp gets too cold, like in February, the moisture in the log freezes, and stays put. I know wind will dry out the ground very fast, (learned that working at a golf course when much younger) so it would do the same to split wood. I also figure the smaller the pieces, the more surface area overall, the faster it will dry. But I also think that makes it burn faster, I prefer some larger logs for the over nights. John Mc explained it quite well, thank you.