Storage & Moisture content
The moisture content of wood is relative to the environment it is stored, this includes temperature and the moisture content of the air. Seasoned firewood can achieve MC of less than 20% if stored under cover from the rain and in a location where the wind can provide good air movement. This means that the firewood you purchase will absorb or lose moisture until it reaches an equilibrium to its surroundings. Kiln dried firewood is usually sold with a MC of around 10-15%, however, if this is then stored outside even in a purpose built log store it will most likely increase to C.20%.
Most seasoned firewood will arrive with a MC of between 20-25%, which will decrease if stored using the keep the rain off and let the wind in method. The best time to purchase seasoned firewood is during Spring time, this allows the logs to be at their optimum dryness for when they will be needed during the following Winter. Try to store all the firewood you will need for a season or if you are running low order more as soon as you have room so they can also start to dry further.