Moisture Content Targets By Region

Wood doesn't have one "correct" moisture content — it has a target that depends on where the finished piece will actually live, because wood settles toward the moisture content of the air around it (its equilibrium moisture content, or EMC) and stays there, moving with the seasons, for the rest of its life.

Why a single national target doesn't work

Indoor EMC in a heated, air-conditioned home varies by region because outdoor humidity, heating season length, and typical indoor climate control all differ. A shop in the humid Southeast and a shop in the arid Southwest are not preparing wood for the same destination climate, and building furniture to one region's target for delivery to another is exactly how a "perfectly dry" tabletop ends up cupping or gapping at its buyer's house six states away.

Commonly cited target ranges by US region

• Humid Southeast / Gulf Coast: roughly 10–14% EMC indoors, reflecting persistently high ambient humidity even with air conditioning running most of the year.
• Pacific Northwest / coastal: roughly 9–12% EMC, moderated by mild but damp conditions.
• Southwest / arid interior: roughly 4–8% EMC — genuinely dry indoor air, especially in winter with heating running.
• Midwest / Northeast (four-season, heated homes): roughly 6–10% EMC, with a real seasonal swing between a dry heated winter and a more humid summer.
• Mountain West / high elevation: roughly 5–9% EMC, similar logic to the arid Southwest but with more seasonal variation.

These are commonly cited working ranges, not laboratory constants — actual EMC in any specific room depends on that room's heating, air conditioning, and how tightly it's sealed, which is why a moisture meter reading on your own material beats a regional table every time you have the option.

The practical rule

Season your wood — or buy it already kiln-dried — to within a percentage point or two of the destination's expected indoor EMC, not the shop's own ambient humidity, and not a generic "8% is dry enough" rule of thumb. A piece built in a humid basement shop and delivered to an arid, centrally-heated home will keep drying and shrinking for months after delivery no matter how "finished" it looked on the day it left the shop.

Once you know the starting moisture content and the target, the actual dimensional consequence — how much a specific board of a specific species and width will move getting there — is a calculation, not a guess: run the numbers in the wood movement calculator rather than relying on a flat percentage rule, since species-specific shrinkage coefficients vary by roughly a factor of three across the woods on this site.

Measuring instead of estimating

A pin-type or pinless moisture meter is the only way to know your actual starting point with confidence; regional EMC tables (including the one above) are a planning tool for before you have material in hand, not a substitute for measuring the board you're about to use. See /reference/moisture-content-targets-by-end-use/ for how the target itself should shift again depending on whether the piece is an outdoor project, an unheated garage build, or fine interior furniture — end use moves the target as much as region does.

Home-improvement projects that mix lumber with other trades — flooring going down before drywall finishing has fully dried a room, for instance — face this same equilibrium problem from the building-materials side rather than the furniture side; GetTheAmount covers project-planning math for that adjacent world of home-improvement calculations, if a build crosses from shop furniture into the house itself.

A worked comparison across two regions

Take a 12"-wide white-oak panel built and finished at 12% moisture content in a humid-region shop, then shipped to a dry, centrally-heated home in the arid Southwest that settles closer to 6% EMC in winter. Using white oak's tangential shrinkage coefficient, the wood movement calculator puts that swing at -0.252" (-6.40mm) across the panel's width — a real, visible amount of shrinkage for a panel built without anticipating the destination climate, enough to open a gap at a breadboard end or crack a rigidly framed panel that wasn't designed to move. Reverse the shipping direction — the same panel built dry in the Southwest and delivered into a humid Gulf Coast home — and the panel gains essentially the same 0.252" back as it swells toward the more humid destination's higher EMC, which is the scenario more likely to bind a drawer or door rather than open a gap.

Why the destination, not the origin, should set the target

A shop's own regional humidity is only relevant to how the wood is stored and worked before it ships — it has no bearing on where the finished piece will eventually settle once it's delivered and living in a different climate. Builders who regularly ship furniture across regions (or take custom commissions from out-of-state clients) build this destination-first thinking into their process from the start: acclimating stock to a target EMC before final glue-up and joinery, not just before the wood is initially milled, so the piece is dimensionally close to its eventual equilibrium by the time joints are cut and panels are captured in frames.