What has the summer left on a seasonal home before the owners arrive?

Lay the calendar of an absence over the Naples weather record and the two line up closely.

Cambridge Dictionary defines a snowbird as “an older person who lives in a cool place in summer and somewhere warmer in winter”, and a seasonal resident keeps a calendar of that kind: here for the cooler months, away for the hot ones. The house stays behind for the part of the year the weather record marks as the heaviest.

Arithmetic over NOAA's 1991 to 2020 monthly normals for Naples Municipal Airport puts 32.67 of the year's 49.55 inches of normal rain in June, July, August and September, about 65.9 percent in four months, while the drier half of the table is described under the dry season. For Southwest Florida, NWS Tampa Bay dates the rainy season from May 15 to October 15. The National Hurricane Center's Atlantic hurricane season runs from June 1 to November 30. The full table sits under the twelve months of Naples normals.

So the months an owner is away are the rainy season and most of the hurricane season, and the months an owner returns are the driest stretch of the table. No source read ties growth or grime to the absence itself. The same weather reaches an occupied house next door; the difference is that nobody at the empty one sees it build.

The roof documents describe growth that needs water and takes time to show, which is a good description of a roof left alone through a wet summer.

ARMA ties roof algae to the spots where moisture dwells, names coastal or humid climates as the most conducive to it, and adds that “By the time the algae is visible, it likely has been present for several months or longer.” NWS Miami puts southeast Florida summer dew points in the lower to middle 70s, and how dew and dew point reach a roof is taken up under whether Naples humidity is why exteriors get dirty.

On tile, TRI Alliance names mildew, algae and moss together. What each of them grows on, and why so many different growths get called by one name, is set out under why everything in Naples grows mildew.

What a cleaning cannot say is anything about the roof under the growth. The condition of a roof after a summer is a licensed roofing contractor's question. Whether a roof can be cleaned once the cooler, drier months arrive is answered under whether a roof can be cleaned in the winter.

An irrigation controller runs on its schedule whether or not anyone is home.

UF/IFAS writes that “Many municipalities have few timing or quantity restrictions on using reclaimed water for irrigation,” and that over-watering with reclaimed water is a common problem. A head that reaches a window wets it on every cycle through the months away, and water that dries on glass leaves behind what it carried. Whether that water leaves marks is its own question, taken up under whether reclaimed irrigation water stains exteriors.

Lovebugs fly in some of the same months: the second of the two yearly flights UF/IFAS describes falls in August and September, and the insect itself is defined under love bugs. What their remains do on glass is a separate question, taken up under whether love bugs can be cleaned off windows.

When the house is cleaned, one condition ties the glass to the roof. ARMA's roof bulletin says algae discoloration may be lightened with household bleach and water, the National Glass Association counts bleach among possible harms to laminated glass, and PGT builds its hurricane windows and doors with laminated glass by its own account; on a house with impact windows, keeping roof solution off that glass is a technical requirement of the job.

The driveway and the walkways sit through the same rain as the roof, with leaves and runoff added.

TRI Alliance's list of the surfaces where mildew, algae and moss grow in many climates includes driveways alongside glass and roof tile. EPA's home guide to mold explains what feeds the organic side of it: outdoors, “molds play a part in nature by breaking down dead organic matter such as fallen leaves and dead trees,” and “There are many types of mold, and none of them will grow without water or moisture.” A paver surface with leaves on it through a wet summer offers both the organic matter and the water.

That is a description of the conditions and not a reading of any particular driveway. Dark patches on pavers can be several different things, and none of them can be named from a page.

The National Hurricane Center's season, June 1 to November 30, covers nearly the whole absence, and it adds a different kind of question to the list.

Leaves, branches and marks left by a storm are one thing; possible storm damage is another, and it belongs with the insurer and the right trade rather than with a cleaning. How those two get told apart is set out under whether exterior cleaning can remove storm debris stains.

For the roof, the pavers and the glass of a seasonal home, 239 Exteriors offers a free estimate, by phone at 239-500-WASH or through the estimate form and its “More than one service” choice.