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McNair, Virginia

Community in Fairfax County, Virginia

Air quality

The air at McNair

Index 48, good, led by fine particles. Read at 12 PM from its reporting area, Northern Virginia (VA), 4 miles off.

48Good
  • Fine particles (PM2.5)48Good21.4 mi
  • Ozone14Good9 ppb19.8 mi
  • Coarse particles (PM10)13Good-
  • Nitrogen dioxide5Good5.3 ppb21.2 mi
  • Carbon monoxide-0.4 ppm21.4 mi

The days ahead

Good each day through Sun Oct 18, led by fine particles. Yesterday measured 28, good.

Smoke, the next 45 hours

Little smoke near the ground through Sun 8 AM: the index from smoke stays at 6 or under.

FriSatSun

Precipitation

What has fallen at McNair

0.01 in in the last 24 hours, and none in the 2 days before, to Fri 11 AM. Measured by radar and rain gauges, as water.

Last 24 hours
0.01in
Last 3 days
0.01in

Visibility

How far you can see at McNair, the next 45 hours

Visibility stays 6 miles or more through Sun 8 AM, lowest 7 miles Sat 4 AM.

FriSatSun

On the radar over McNair, VirginiaReflectivityStorm topsRain rateRain, last 24 hoursForecast temperatureForecast rain totalEvery picture

What is measuring near here

The 5 instruments nearest McNair, how far away each one is, how high it stands, and what kind of measurement it makes. The nearest is 0.4 miles away.

measured now3 instruments

measured daily2 instruments

Herndon 2.0 SWVA-FX-141

In a volunteer observer's own ground/0.4 mi away/331 ft/33 ft below here

precip, snowfall, snow depth

Rank-

Station report

The weather at Washington/Dulles, drawn

The nearest airport reporting now, 2.2 mi from McNair, Virginia. From its report of Oct 16, 2026, 12:03 PM local time: 3 of its 6 sheets.

The sky

Scattered at 900 ft; visibility 10 mi or more.

Section of the sky over Washington/Dulles, height above the station to scale: scattered cloud with its base at 900 feet, and visibility of 10 mi or more.1122334455667788AABBCCDDEE© 2026 STORM STATION 247THE FIELD BOOKSTATION REPORT IADFIG. A THE SKY OVER WASHINGTON/DULLESSECTION, HEIGHT ABOVE THE STATION TO SCALE, EACH LAYER AT THE HEIGHT OF ITS BASE AS REPORTED; COVER IN EIGHTHS OF THE SKY; TOPS NOT MEASUREDFT ABOVE THE STATION05001,0001,5002,0002,5003,000ETAGESLOWTHE STATIONTHE CEILOMETER READS TO 12,000 FT, ABOVE THIS SHEETSCT 900 FTSCATTERED, 3 TO 4 EIGHTHS OF THE SKYVISIBILITY, MILES: 10 MI OR MORE0510TITLEWashington/Dulles, the skySTATION REPORT · ASOS IADTYPESECTIONSCALEHEIGHT TO SCALEREVAS REPORTED SHEET 1 of 6DATE2026-10-16IDSR-IAD-1DRAWN AS linework on paperSOURCES FB-SKY-001, FB-SKY-017, FB-SKY-016, FB-SKY-018

The air

72.0 F with a dew point of 66.0 F, 81 per cent relative humidity. Air lifted from the station would cool to its dew point, where cloud forms, about 1,400 ft up; the lowest cloud reported is at 900 ft.

Chart of the air at Washington/Dulles: temperature 72.0 degrees Fahrenheit and dew point 66.0, 81 per cent relative humidity; air lifted from the station cools along the dry rate and meets its dew point about 1,400 feet above the station, against the lowest cloud reported at 900 feet; height to scale.1122334455667788AABBCCDDEE© 2026 STORM STATION 247THE FIELD BOOKSTATION REPORT IADFIG. B THE AIR AT WASHINGTON/DULLESTHE REPORTED TEMPERATURE AND DEW POINT, AND AIR LIFTED FROM THE STATION WITHOUT MIXING UNTIL IT SATURATES; HEIGHT ABOVE THE STATION TO SCALEFT ABOVE THE STATION01,0002,0003,00050 F60 F70 F80 FSATURATES 1,400 FT ABOVE THE STATION, AT 64.6 FLOWEST CLOUD REPORTED, SCT 900 FTTEMPERATURE 72.0 FDEW POINT 66.0 FSPREAD 6.0 FRELATIVE HUMIDITY 81 PER CENTTHE AIR COOLS ABOUT 5.4 F EACH 1,000 FT IT RISES, AND ITS DEW POINT ABOUT 1 FSOLID: THE LIFTED AIR'S TEMPERATURE; DASHED: ITS DEW POINTTITLEWashington/Dulles, the airSTATION REPORT · ASOS IADTYPECHARTSCALEHEIGHT TO SCALEREVAS REPORTED SHEET 2 of 6DATE2026-10-16IDSR-IAD-2DRAWN AS linework on paperSOURCES FB-WAT-002, FB-ENG-011, FB-ENG-005

The wind

From the south southwest (210 degrees) at 13 mph: force 4, a moderate breeze on the Beaufort scale. The strongest gust today was 21 mph.

Plan of the wind at Washington/Dulles, north up: blowing from 210 degrees, the south southwest, at 13 miles an hour; beside it the Beaufort scale from calm to hurricane force, force 4, moderate breeze, marked.1122334455667788AABBCCDDEE© 2026 STORM STATION 247THE FIELD BOOKSTATION REPORT IADFIG. C THE WIND AT WASHINGTON/DULLESPLAN, NORTH UP: THE WIND AS REPORTED, AND WHERE IT SITS ON THE BEAUFORT SCALENESWTHE STATIONFROM 210°BEAUFORT FORCELEAST WIND, MPH0CALM01LIGHT AIR12LIGHT BREEZE43GENTLE BREEZE84MODERATE BREEZE13NOW, 13 MPH5FRESH BREEZE196STRONG BREEZE257NEAR GALE328GALE399STRONG GALE4710STORM5511VIOLENT STORM6412HURRICANE FORCE73TITLEWashington/Dulles, the windSTATION REPORT · ASOS IADTYPEPLAN north upSCALENOT TO SCALEREVAS REPORTED SHEET 3 of 6DATE2026-10-16IDSR-IAD-3DRAWN AS linework on paperSOURCES FB-EVT-150, FB-ENG-008, FB-INS-002

The full report of Washington/Dulles, in 6 sheets, each beside the Field Book plates that explain it

0in

Snow on the ground

Measured at Sterling WFO (KCIV2), 4.6 miles from here, read 16 Oct, 08:00. measured daily

Elsewhere in Virginia

16 places, each with its own forecast and its own instruments.

Near McNair

The nearest places, each with its own forecast and the instruments nearest it.

Near McNair

River and lake gauges