The best time of year to paint a house exterior in Maryland

In Montgomery County, Prince George's County and Washington, DC, the most reliable exterior painting months are May through June and September through mid October. Both windows offer mild temperatures, moderate humidity and enough daylight for a full working day.

July and August work too, as long as the crew follows the shade around the house and avoids painting walls in direct afternoon sun. April and late October can be good or bad depending on the week. From November through March, most days in this region are too cold or too damp for exterior coatings to cure properly.

Every exterior paint label lists a minimum air and surface temperature. For most modern acrylic house paints it is somewhere between 35 and 50 degrees Fahrenheit, and it must stay above that while the paint dries, including overnight. The surface also has to stay at least 5 degrees above the dew point, or moisture condenses on the wall and the paint can wash out, streak or fail to bond.

Humidity matters as much as temperature. Fresh latex paint that gets hit by heavy evening dew can show surfactant leaching: sticky, brownish streaks that appear a day or two later. It is mostly cosmetic and washes off, but it is avoidable by stopping work early enough for the paint to set before the dew falls.

Fall is a favorite season for exterior work here, with dry air and comfortable temperatures. The catch is the length of the usable day. Cold, clear nights leave siding wet with dew until mid morning, and the dew point catches up with the falling surface temperature by mid afternoon. A September day might allow eight hours of painting. A late October day might allow four.

That is why we plan fall exterior jobs by the side of the house. East walls dry first in the morning, west walls stay warm latest in the afternoon, and north walls may only be paintable in a short window around midday. Our exterior painting crews schedule each elevation around that window instead of forcing a full day.

Interior projects can happen any month, which is why many homeowners pair the two: exteriors in the warm season, then interior painting, cabinets and ceilings through the winter. The calendar below shows how each kind of project fits the Maryland year.

The painting window is only part of the schedule. Siding should be washed and fully dry before primer, which usually means soft washing at least a day or two ahead. Rotted trim, sills and fascia need to be replaced and primed before finish coats, so wood rot repair is planned into the first days of the job rather than discovered halfway through.

Decks follow slightly different rules. New pressure-treated lumber usually needs to dry for several weeks before it will absorb stain, and stain should not go on in direct hot sun. See our notes on deck and fence staining for timing.

Spring and early fall fill up first. If you want a May or September start, the best time to get estimates is late winter for spring work and early summer for fall work. That gives time to compare itemized bids, choose colors and, for older homes, plan lead-safe prep before the weather turns favorable.

If your home was built before 1978, read our guide to lead paint in older Maryland and DC homes before you schedule, since containment and cleanup add time to an exterior job.