Washington County heating and cooling, county by county: 327 square miles of Tennessee lying west of the Johnson City metro's centre, 8 ZIP codes, and a climate record read from BRISTOL TRI CITY AP, TN US. TempReach USA connects you with an independent local HVAC technician; this page sets out the county's own figures.
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Washington County in one paragraph: 327 square miles in Tennessee, 8 ZIP codes, a heating climate pressure read from the normals at BRISTOL TRI CITY AP, TN US, and housing that answers 4,150 heating degree days against 1,104 cooling degree days a year. TempReach USA is a referral service, not an HVAC company — one call connects you with an independent local HVAC technician serving this county.
The station for this county's metro is BRISTOL TRI CITY AP, TN US, and its NOAA 1991-2020 normals are the source of every figure in this section. Precipitation averages 43.97 inches a year; the temperature record averages 56.6 degrees, built from 23.0 days at 90 or above and 94.2 nights at or below freezing; the workload totals 4,150 heating degree days and 1,104 cooling degree days. Washington County is read through that record throughout this page.
Divide Washington County's cold by its coverage and the heating diary sharpens: 8 ZIP codes over 327 square miles, 40.8 square miles per code on average, the codes running from 37601 to 37690. A furnace failure in the code nearest the metro reads differently from one at the county's far edge — not in the fault, which is the same worn igniter or tired blower, but in everything around it: the drive, the house's decade, the odds the system has already been replaced once. The cold itself, 4,150 heating degree days of it, is shared; the ground it is answered on is not.
Set the county inside its metro and the picture completes. Washington County answers to the Johnson City metro's data — its housing profile, its problem ranking, its climate station — but the county is where that data touches ground: 5 communities, 8 ZIP codes, one county's worth of systems ageing under the record kept at BRISTOL TRI CITY AP, TN US. This page is that ground-level reading, kept separate from the metro page so the local detail is never averaged away.
There is a scale fact hidden in Washington County's ZIP codes: 8 codes across 327 square miles works out to 40.8 square miles per code, which makes a service call here a matter of ground as well as of systems. The codes on the metro-facing side of the county — the county sits west of the Johnson City metro's centre — and the codes at its far edge hold different ground, but both ends ask the same climate questions of their heating and cooling, at different distances.
Position first: Washington County lies west of the Johnson City metro's centre, roughly 10 miles from the metro's centre as the map measures it, with Carter County, Unicoi County among the counties around it. Neighbourhood at county scale matters to heating and cooling because systems do not respect the border — the same subdivisions' building decades continue across it, the same cold snaps and heat waves examine both sides in the same night — while each county's page, this one included, keeps the local figures distinct.
Consider what one year asks of a system in Washington County: a cooling season measured at 1,104 degree days, a heating season at 4,150, 23.0 days of serious heat and 94.2 freezing nights, and 43.97 inches of precipitation working on every outdoor unit through all of it. No single figure is remarkable; the combination is the county's climate, and it is the combination a system has to survive for fifteen or twenty years. The service patterns described on this page are that arithmetic, playing out across 327 square miles of housing.
Start the county at its named places: Johnson City, Jonesborough, Oak Grove, Central head a list of 5 communities recorded in Washington County. The list matters to heating and cooling because communities concentrate the housing — a street of homes built in one decade produces one kind of service diary, the next community's different decade produces another — and because the roads between the named places are part of the working day here. The county page's climate record is shared; the ground it lands on is divided among these names.
Age is the county's second climate. The Johnson City metro's median home was built in 1982, and 47.6% of its homes predate 1980 — in Washington County, that share is the older districts and the long-settled communities, where ductwork from an earlier equipment era still serves replacement systems. The newer share, 24.0% built since 2000, concentrates in the county's growth edges. The service diary divides along that line: deep equipment-and-duct conversations at the old end, first-replacement and control conversations at the new one.
Coverage, for Washington County, is a set of overlapping maps. The land map is 327 square miles. The address map is 8 ZIP codes and 5 listed communities. The service map is the Johnson City metro, whose coverage the county sits inside — west of the Johnson City metro's centre, roughly 10 miles from its centre. The weather map is one station's record, kept at BRISTOL TRI CITY AP, TN US. A home in this county lives on all four maps at once, and its heating and cooling needs are set by the combination.
City pages carry the metro-wide homework — housing eras, the problem ranking, services in depth. This county sits inside their coverage.
Population 71,455
Population 6,056
Population 4,483
Population 1,944
Population 1,606
TempReach USA is not an HVAC company. We employ no heating or cooling technicians, we run no service trucks, and we do not carry out HVAC work of any kind. This website and its call center exist for one purpose: to connect homeowners with independent local heating and cooling professionals who serve their area. When you call the number on this site, your call is routed to such a professional. From that point, everything about the job belongs to that professional and to you: the assessment, the work itself, the scheduling, what you are charged, and the terms of any agreement you reach. The professional who takes your job is solely responsible for it. The technician who arrives at your home runs their own business; they are not an employee, agent or subcontractor of TempReach USA. Our part is the information on these pages — assembled from Census Bureau housing data and NOAA climate records for each metro — and the routing of your call. We state this plainly on purpose: you should know exactly who you are hiring before anyone picks up a wrench or a gauge.
One call connects you with an independent local heating and cooling professional serving Washington County and the Johnson City metro.
Call center hours: Mon-Fri 7:00 AM-10:00 PM ET | Sat 8:00 AM-10:00 PM ET | Sun 7:00 AM-9:00 PM ET