When wood is completely dry and is not a type of artificial wood, the combustion temperature is generally 451 degrees Fahrenheit, according to the Argonne National Laboratory. However, there are many variables, such as moisture, oxygen ability and wood density, that come into play.
If wood has any moisture on or within it, it can take longer for it to catch fire. This is why it is important to find dry sticks and leaves when creating a fire. The amount of oxygen is important because oxygen is necessary to start and grow a fire. The type of wood and the size of the wood also factor in. Wood that is denser releases more heat, burns hotter and burns slower because it has a high energy content. Examples of dense wood include oak and maple.
With size, the wood should fit into the burning appliance, and one should be able to stoke it without difficulty. Stoking allows one to maintain a fire. On average, 3 inches in length is ideal for furnaces and stoves, while 14 to 18 inches in length is ideal for fireplaces.