Firewood Drying Time Chart: Seasoning Guide by Species, Region and Season

How long firewood takes to dry depends on species, where you live and when you cut. A chart that only says "oak takes 18 months" misses two thirds of the answer. This guide by Kiln Dried Logs provides a full firewood drying time chart by species, a regional climate adjustment table covering conditions from Scandinavia to the US South, and a seasonal cutting calendar so you can plan a firewood supply that is actually ready when you need it.

Firewood Drying Time Chart by Species

The timelines below assume split logs of around 15cm diameter, covered storage with open sides and good airflow, and a temperate climate baseline. Two drying methods are compared: traditional air seasoning and kiln drying.

Starting moisture content figures sourced from the USDA Forest Products Laboratory, Wood Handbook: Wood as an Engineering Material (FPL-GTR-282, 2021).

For a full comparison of what each drying method involves, see our guide to seasoned logs vs kiln-dried logs.

Regional Climate Adjustment: How Much Longer Your Firewood Will Take

Climate is the single biggest variable outside your control. The same species stacked the same way can take twice as long to season in a wet maritime climate as in a dry continental one.

Buyers in dry continental climates can reduce baseline estimates by two to three months. Those in maritime or high-humidity climates should add months rather than assume the chart baseline applies. For tropical and monsoon climates, air seasoning is too inconsistent to deliver reliably dry firewood.

Seasonal Cutting Calendar: When You Cut Determines When You Burn

The season you cut or receive green wood directly controls when it will be ready. This calendar applies to the northern hemisphere with adjustments for southern hemisphere readers at the end of each section.

Spring Cutting (March to May): The Optimal Window

Cutting and splitting in early spring gives firewood the entire warm season for active drying. Most evaporation happens during warm, lower-humidity months. For ash and birch in a temperate climate, spring-cut logs can reach below 20% moisture by the following autumn, roughly 12 to 14 months. For oak, spring cutting still means the wood will not be ready until at minimum the following winter. Southern hemisphere readers should apply the same logic to September through November.

Summer Cutting (June to August)

Summer cutting loses part of the optimal drying window but benefits from immediate warm temperatures. Pine and larch cut in June can be usable by the following spring, around 9 to 11 months later. Dense hardwoods follow their own timeline regardless of whether they are cut in April or July; for oak, a month or two of summer head start makes little practical difference to the overall seasoning period.

Autumn and Winter Cutting: The Difficult Window

Wood cut in autumn immediately enters months of lower temperatures and higher humidity before meaningful drying can begin. Add 2 to 4 months to baseline estimates depending on how cold and wet your winters are. In cold continental climates, freeze-thaw cycles through winter can actually help break down wood fibres, partially offsetting the slow evaporation rate. In mild, wet maritime climates, winter cutting simply delays the start of drying with no compensating benefit.

Spring cutting is the most efficient natural timeline for ash in a temperate climate. Autumn-cut wood loses the best drying months immediately and requires planning a full additional season ahead. The drying clock starts the moment wood is split, not when the tree was felled.

For practical guidance on how to stack wood correctly to maximise airflow and drying speed, see our guide to firewood stacking methods.

5 Factors That Affect Your Actual Drying Time

Species, region and season set the baseline. These five practical variables determine whether your wood arrives on schedule or runs a full season over.

Log Diameter: The Most Controllable Factor

Moisture travels from the core outward to the surface. At 10cm diameter, the travel distance is 5cm. At 20cm it doubles to 10cm, resulting in 3 to 4 times longer drying. Splitting a 30cm round into quarters nearly doubles the exposed surface area and can cut drying time by 50 to 60 percent, according to guidance from Cornell Cooperative Extension. The optimal split size for reliable seasoning is 10 to 15cm across. Split as soon as possible after cutting; a whole round sitting for three months has barely dried at all.

Storage Setup: Open Sides, Covered Top

A fully enclosed or tightly wrapped stack traps humidity and prevents drying. The correct setup is a solid roof, open slatted sides and a raised base at least 15cm off the ground. Face the open side toward prevailing sun exposure. In the northern hemisphere, south-facing is typically best. Enclosed sheds without ventilation slow drying by up to 30 percent even in warm climates, because airflow rather than temperature does most of the work of removing moisture.

Bark, Ground Contact and Starting Moisture

Bark slows drying by 10 to 20 percent by acting as a moisture barrier, but splitting already exposes enough surface area for most species. Ground contact wicks soil moisture upward into the bottom layer; logs sitting directly on soil can read 5 to 10 percent higher moisture than the rest of the stack. Always use pallets, bricks or a purpose-built elevated base. Starting moisture also varies by season: trees felled in late winter when sap is at its lowest begin the drying process with a natural head start compared to summer-felled wood.

For the full process of controlled commercial drying, see our guide to how kiln drying works.

How to Tell When Firewood Is Ready to Burn

Appearance and sound give useful early signals. A moisture meter gives the only number worth relying on for both safety and legal compliance.

Moisture Meter Reading

Insert probes into the middle of a freshly split face, not the outer surface. Target below 20 percent moisture content. In the UK this is a legal requirement for commercially sold firewood under 2 cubic metres under the Ready to Burn standard. In most other countries it is the recognised quality benchmark for efficient, clean burning. Test multiple pieces across different parts of a stack, as moisture varies significantly from log to log even in a well-stored batch.

Visual and Sound Checks

Ready firewood has grey or darkened cut ends with visible radial cracks, and produces a clear hollow ring when two logs are knocked together. Wood that is not yet ready shows pale yellow or white cut ends, sounds dull when struck and feels heavier than expected. Weight is a reliable field check: a well-seasoned hardwood log should weigh roughly half what the equivalent green log weighed at the time of cutting.

Air Seasoning vs Kiln-Dried: Choosing the Right Approach

Air seasoning costs nothing beyond time and storage. Kiln-dried wood is available immediately at guaranteed moisture content. Which approach works depends on your climate, timeline and how you plan to use the wood.

Air seasoning is practical when you have 12 to 24 months of lead time before you need the wood, covered outdoor storage with good airflow and no compliance deadline. Lighter species in dry climates are the best candidates: birch in Central Europe or ash in temperate inland regions can reliably reach below 20 percent through air drying alone within a reasonable timeframe.

Kiln-dried wood is the practical choice when you need fuel this season, live in a high-humidity climate where dense hardwoods struggle to air-season reliably, lack storage space, or need guaranteed moisture content for regulatory or quality reasons. Professionally kiln-dried logs arrive at below 20 percent moisture with consistent results regardless of season, species or regional climate.

Shop kiln-dried hardwood logs, Woodsure certified and delivered below 18% moisture, with free delivery on orders over £100.

Frequently Asked Questions

The most common questions about firewood drying times from buyers and self-cutters.

How long does firewood take to dry?

Softwoods such as pine, larch and spruce take 6 to 12 months under good air-drying conditions in a temperate climate. Lighter hardwoods including birch, ash and maple need 9 to 18 months. Dense hardwoods such as oak, beech and hickory typically require 18 to 24 months. Humid maritime climates add 2 to 4 months to any of these figures. Kiln drying reduces all species to 3 to 8 weeks.

Does splitting firewood really speed up drying?

Yes, significantly. Splitting a 30cm round into quarters approximately doubles the exposed surface area, reducing drying time by 50 to 60 percent. Moisture escapes primarily through the cut grain surfaces, not through bark. Splitting immediately after cutting starts the drying clock properly; a whole unsplit round can sit for months with minimal moisture loss.

Can firewood dry in winter?

Yes, but at reduced speed. In cold continental climates, freeze-thaw cycles through winter can help break down wood fibres and accelerate drying once temperatures rise again. In mild, wet maritime climates, winter offers very little active drying. Effective evaporation in most temperate regions happens primarily during the warmer months, roughly April through September in the northern hemisphere.

What moisture content should firewood be before burning?

Below 20 percent is the recognised standard for clean, efficient burning. Wood above 25 percent moisture wastes energy boiling off water rather than producing heat, produces significantly more smoke, and causes creosote to accumulate in flues and chimneys faster. Some high-efficiency stoves perform best with wood below 15 percent. A basic moisture meter, available from most hardware retailers, is the only reliable way to confirm readiness.

For a full breakdown of hardwood and softwood characteristics and how density affects drying, see our guide to understanding the difference between hard and soft wood.

Know Exactly When Your Firewood Will Be Ready

A firewood drying time chart is most useful when it accounts for what actually varies: species density, regional humidity and the season you start drying. The tables above give you a baseline by species, a regional multiplier and a seasonal calendar to plan realistically rather than optimistically. For buyers in humid climates or anyone who needs fuel this season, kiln-dried logs remove the uncertainty entirely and deliver consistent moisture content from the moment of delivery.

Shop kiln-dried logs with free delivery on orders over £100, Woodsure certified and ready to burn on arrival.