There are ways of telling how dry your firewood is such as knocking 2 logs together and getting a nice hollow sound, rather than a dull thud, or observing how many cracks are appearing in the log end. Well cracked will normally suggest, well dried. Weight is also a factor as the wetter the log, the heavier it will be, but one real characteristic of our kiln dried logs is the lovely sweet aroma of the logs.
However, the really best way to check the moisture content is by using a moisture meter. This will give you a pretty good guide as the actual reading of the firewood, both inside and out. Check inside by splitting a log open. Just be aware however that moisture meters are not always 100% accurate, particularly the very cheap ones. Also, useful to note, with kiln dried logs, the outside of the log will measure lower than the inside, but the average across the log should be below 20%.