Firewood Moisture Content: The Difference Between Wood That Burns and Wood That Struggles
Firewood needs time, airflow and the right storage conditions to dry properly. Learn what moisture percentages mean, how to test firewood correctly and what to ask a supplier before you order.
Dry wood burns cleaner and more efficiently.
For a practical home-burning target, moisture readings around 15–20% on the freshly split interior face are commonly recommended.
15–20% moisture
Moisture matters
Split before testing
Airflow dries wood
Time varies
Wet firewood makes your fire work harder
Before wet wood can burn efficiently, energy has to be used to heat and evaporate the water inside it. That can mean harder starts, lower firebox temperatures, more visible smoke and less useful heat in the room.
Dry wood starts more easily
More energy reaches the room
Cool, smoky fires are undesirable
Green, seasoned and kiln-dried are not the same thing
These terms describe how firewood has been handled, but the actual moisture reading is more useful than the label alone.
Recently harvested wood
Dried naturally over time
Dried with added heat
CanFirewood practical target
For ready-to-burn firewood, readings around 15–20% on the freshly split interior are a useful benchmark. A single surface reading on the outside of a log can be misleading.
Test the inside of the wood—not just the dry-looking surface
A basic pin-style moisture meter is one of the easiest ways to check whether firewood is ready to burn. Firewood moisture content is the most important variable when it comes to a clean burn and heat output.
How to get a useful reading
Testing several pieces gives you a better picture of the load than checking one convenient log.
- Choose several representative pieces from different parts of the stack.
- Bring a piece to roughly room temperature if practical; very cold wood can affect some meters.
- Split the piece again to expose a fresh interior face.
- Push the meter pins into the newly exposed face, ideally across the grain if your meter instructions recommend it.
- Test more than one spot and more than one piece. Look for the pattern, not one perfect number.
Four things help firewood dry
There is no universal “six months” or “one year” rule. Drying time changes with species, climate, log size, when it was split and how the stack is exposed.
Split It
Give It Air
Use Sun & Warmth
Give It Time
A good stack keeps drying after delivery
Firewood should be protected from prolonged wetting without trapping moisture around the stack.
✓ Better storage habits
- Keep the wood off soil and standing water.
- Choose a location with good airflow.
- Cover the top of the stack from rain and snow while leaving the sides open where practical.
- Stack loosely enough for air to move between pieces.
- Rotate older wood forward so it gets burned first.
- Keep only a limited amount indoors near the appliance and follow fire-safety clearances.
× Common drying mistakes
- Wrapping the entire pile tightly in an impermeable tarp.
- Stacking directly on wet ground.
- Leaving large rounds unsplit and expecting them to dry quickly.
- Putting freshly cut wood into a closed shed with little ventilation.
- Assuming wood is dry because the ends are cracked or the bark is loose.
- Bringing a large quantity of wet firewood inside the home to “finish drying.”
Questions worth asking the supplier
Good suppliers should be able to explain their process clearly, even if they do not promise an exact moisture percentage for every piece.
When was the wood split?
Why it helps: Split wood normally dries much faster than rounds.
What you learn: Whether the drying clock really started months ago.
How has it been stored?
Why it helps: Airflow and rain protection matter as much as elapsed time.
What you learn: Whether “seasoned” means properly stacked or simply old.
Do you check moisture?
Why it helps: A meter can provide useful evidence when used correctly.
What you learn: Whether the seller has a measurable drying standard.
Where is the reading taken?
Why it helps: Outside surfaces can be much drier than the centre.
What you learn: Whether the measurement reflects the interior of the wood.
What species are included?
Why it helps: Species dry at different rates and have different densities.
What you learn: Why some pieces in a mixed load may read differently.
Is it ready to burn now?
Why it helps: Some suppliers sell both green and seasoned inventory.
What you learn: Whether you should burn it this season or store it longer.
Want to dig a little deeper?
Natural Resources Canada, the U.S. EPA and Health Canada all publish practical guidance related to firewood moisture, testing and wood-smoke reduction.