Woodworking by state

Woodworking in New York: Wood Moisture and Outdoor Builds

Month-by-month outdoor wood moisture for 7 places in New York, from 11.0% in New York in April to 15.7% in Binghamton in December, and what it means for buying lumber, gluing up and finishing.

7Places with monthly data

12.0%Driest year average, New York

14.1%Dampest year average, Binghamton

Wood trades moisture with the air around it until it reaches a balance called the equilibrium moisture content (EMC). The numbers on this page are the average EMC of wood kept outdoors under cover (out of direct rain and sun) for each month, calculated by the USDA Forest Products Laboratory from at least 30 years of NOAA humidity and temperature records. Wood that gets rained on will be wetter for a while; wood inside a heated or air-conditioned house will be drier. The general advice below uses New York as the reference city.

Outdoor wood moisture in New York, month by month

Average outdoor equilibrium moisture content of wood (%), New York. Driest month Wettest month
City	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec	Year
New York	12.2	11.9	11.5	11.0	11.5	11.8	11.8	12.4	12.6	12.3	12.5	12.3	12.0
Albany	13.5	12.8	12.4	11.4	12.0	12.4	12.6	13.6	14.3	13.8	13.9	14.2	13.1
Binghamton	15.0	14.3	13.7	12.5	12.6	13.2	13.2	14.3	15.1	14.4	15.0	15.7	14.1
Buffalo	15.0	14.9	14.2	12.6	12.2	12.4	12.3	13.2	13.7	13.7	14.6	15.2	13.7
Islip	13.2	12.7	12.8	12.5	12.4	12.4	13.3	13.6	13.9	13.7	13.4	12.8	13.1
Rochester	14.3	14.3	13.7	12.5	12.3	12.6	12.6	13.6	14.4	14.2	14.6	15.4	13.7
Syracuse	14.2	13.9	13.4	12.2	12.3	12.6	12.7	13.8	14.6	14.1	14.6	15.1	13.6

City by city

Each city below gets its own numbers and advice. Deck board figures are for a 5½-inch flat-sawn pine board going from the wettest to the driest month.

Woodworking in New York: wood moisture by month

12.0%Year average
11.0%Driest: Apr
12.6%Wettest: Sep
1/32 in.Deck board movement

Moisture barely changes through the year (11.0% to 12.6%), so seasonal movement is small. The main job is letting yard lumber dry toward 12.0% before you build. The driest months, March, April and May, are the best time for staining and painting.

Woodworking in Albany: wood moisture by month

13.1%Year average
11.4%Driest: Apr
14.3%Wettest: Sep
1/32 in.Deck board movement

Outdoor wood ranges from 11.4% in April to 14.3% in September, averaging 13.1%, close to the Handbook's 12% target for exterior wood. On average it is 1.1 points wetter than New York. The driest months, March, April and May, are the best time for staining and painting.

Woodworking in Binghamton: wood moisture by month

14.1%Year average
12.5%Driest: Apr
15.7%Wettest: Dec
1/32 in.Deck board movement

Wood sits on the damp side most of the year, averaging 14.1% with a peak of 15.7% in December. Kiln-dried stock left in an unheated garage will pick up moisture, so store it indoors. On average it is 2.1 points wetter than New York. The driest months, April, May and June, are the best time for staining and painting.

Woodworking in Buffalo: wood moisture by month

13.7%Year average
12.2%Driest: May
15.2%Wettest: Dec
1/32 in.Deck board movement

Wood sits on the damp side most of the year, averaging 13.7% with a peak of 15.2% in December. Kiln-dried stock left in an unheated garage will pick up moisture, so store it indoors. On average it is 1.7 points wetter than New York. The driest months, May, June and July, are the best time for staining and painting.

Woodworking in Islip: wood moisture by month

13.1%Year average
12.4%Driest: May, Jun
13.9%Wettest: Sep
1/32 in.Deck board movement

Moisture barely changes through the year (12.4% to 13.9%), so seasonal movement is small. The main job is letting yard lumber dry toward 13.1% before you build. On average it is 1.1 points wetter than New York. The driest months, April, May and June, are the best time for staining and painting.

Woodworking in Rochester: wood moisture by month

13.7%Year average
12.3%Driest: May
15.4%Wettest: Dec
1/32 in.Deck board movement

Wood sits on the damp side most of the year, averaging 13.7% with a peak of 15.4% in December. Kiln-dried stock left in an unheated garage will pick up moisture, so store it indoors. On average it is 1.7 points wetter than New York. The driest months, April, May and June, are the best time for staining and painting.

Woodworking in Syracuse: wood moisture by month

13.6%Year average
12.2%Driest: Apr
15.1%Wettest: Dec
1/32 in.Deck board movement

Wood sits on the damp side most of the year, averaging 13.6% with a peak of 15.1% in December. Kiln-dried stock left in an unheated garage will pick up moisture, so store it indoors. On average it is 1.6 points wetter than New York. The driest months, April, May and June, are the best time for staining and painting.

What moisture content to aim for

The Wood Handbook's rule is to install wood at the moisture content it will live at, so it moves as little as possible afterward. In New York the year-round outdoor average is 12.0%.

Outdoor projects (decks, benches, planters, siding and trim): the Handbook recommends an average of 12% (individual pieces 9% to 14%), the Handbook's figure for most of the United States.
Indoor furniture and trim: about 8% (6% to 10%), the figure for most of the country.

A pin or pinless moisture meter takes the guesswork out. Check a few boards from each batch, not just one.

How much a deck board moves here

Using the Wood Handbook's shrinkage coefficient for flat-sawn loblolly pine (a common treated-lumber species; Table 13-5), a board 5½ inches wide, the width of a 2x6 or a 5/4 deck board, changes width by:

Estimated width change of a 5½-inch flat-sawn pine board, New York
Change	Moisture change	Width change
Wettest to driest month	12.6% to 11.0%	about 1/32 inch
From 19% ("dry" lumber) to the local average	19% to 12.0%	about 3/32 inch

These are estimates: real boards are rarely perfectly flat-sawn, and western redcedar moves about 10% less than pine. The point is the direction. Lumber bought at 19% will shrink, so gaps between deck boards installed tight will open as it dries.

Acclimating lumber in New York

Bring it home early. Buy lumber a week or more before you build.
Stack it with stickers. Lay straight spacer strips every couple of feet between layers so air reaches every face, and keep the pile off the ground.
Store it where the project will live. Outdoors under cover for outdoor projects; inside the house for indoor furniture.
Measure, don't guess. When moisture meter readings stop changing from one day to the next, the wood is ready.

Damp all year

Outdoor wood in parts of the state stays above 12% in almost every month. Kiln-dried furniture lumber (dried to 6% to 8% at the mill) stored in an unheated garage or shed will drift up toward the outdoor level. The Forest Products Laboratory notes that warming a closed storage space above the outside temperature lowers the moisture level: with an outdoor EMC of 14%, holding the space about 20°F above outside brings it to about 7%. Store furniture stock indoors or in a conditioned room, and build indoor pieces there too.

Damp weather also favors mildew on outdoor finishes. The Wood Handbook advises washing mildew off with a commercial mildew cleaner or diluted household bleach and detergent before refinishing, since new finish over mildew fails early.

Woods and finishes that hold up outdoors

For anything left outside, choose wood that resists decay or wood treated for it. The Wood Handbook's Table 14-1 rates the heartwood of the cedars (including western redcedar), white oaks, black locust and old-growth redwood as resistant or very resistant, Douglas-fir and young-growth redwood as moderately resistant, and most pines, spruces and firs as slightly or not resistant. Use pressure-treated lumber rated for ground contact for posts and anything touching soil.

From the Handbook's Table 16-5: a water-repellent preservative typically lasts 1 to 3 years, semitransparent stain 4 to 8 years on rough-sawn or weathered wood, solid-color stain 6 to 15 years and paint 10 to 20 years. Clear varnish is a poor choice for furniture left in the sun; it generally needs refinishing every 1 to 2 years there.

Best months for outdoor builds and finishing

In New York, outdoor wood is driest in March, April and May and wettest in August, September and November. Lumber dries fastest, and finishes go onto dry wood, in the drier months, so plan staining and painting for then. Avoid sealing wood during the wettest stretch, when it is holding the most moisture it will hold all year. If those months are cold, check the minimum application temperature on the can before you finish. The city sections above give the driest months for each city.

Keep reading

Deciding what to build this season? Start with our list of 9 things worth building instead of buying.

Sources

Monthly EMC for New York: USDA Forest Products Laboratory, Wood Handbook (FPL-GTR-190), Table 13-1. The same values appear in Simpson 1998, Table 2.
Monthly EMC for Albany, Binghamton, Buffalo, Islip, Rochester and Syracuse: Simpson, W.T. 1998. Equilibrium moisture content of wood in outdoor locations in the United States and worldwide. FPL-RN-0268, Table 2
How we got the numbers: Simpson's Table 2 is printed as a scanned image, so we transcribed it from a high-resolution render and read every value three independent ways (two separate text-recognition passes and a visual check). All three agreed on every value, and for the cities that also appear in the Handbook's text table the values match it exactly.
Both tables were calculated by the Forest Products Laboratory from NOAA National Climatic Data Center records (Comparative Climatic Data): the average of morning and afternoon relative humidity and the normal daily temperature for each month, mostly from at least 30 years of observations.
Recommended moisture content (Table 13-2, Figure 13-1), shrinkage coefficients (Table 13-5), decay resistance (Table 14-1) and finish service life (Table 16-5): Wood Handbook (FPL-GTR-190)