McNair, VA Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for McNair, a community in Fairfax County, Virginia.
Tonight
52°F
Mostly Clear
Mostly clear, with a low around 52. South wind around 5 mph.
7-day forecast for McNair
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Tonight | 52°F | Mostly Clear | 5 mph S | 2% |
| Wednesday | 75°F | Mostly Sunny | 5 to 10 mph S | 2% |
| Wednesday Night | 62°F | Mostly Cloudy then Chance Light Rain | 6 to 9 mph S | 51% |
| Thursday | 75°F | Chance Light Rain | 8 to 12 mph S | 43% |
| Thursday Night | 61°F | Chance Light Rain | 2 to 8 mph SW | 50% |
| Friday | 70°F | Rain Likely | 5 mph N | 61% |
| Friday Night | 50°F | Light Rain Likely | 2 to 7 mph NW | 61% |
| Saturday | 65°F | Mostly Sunny | 7 to 12 mph NW | 10% |
| Saturday Night | 43°F | Partly Cloudy | 8 mph NW | 10% |
| Sunday | 61°F | Mostly Sunny | 5 to 8 mph NW | 6% |
| Sunday Night | 42°F | Partly Cloudy then Slight Chance Light Rain | 5 to 8 mph NW | 19% |
| Monday | 61°F | Slight Chance Light Rain | 8 to 15 mph NW | 20% |
| Monday Night | 39°F | Slight Chance Light Rain | 5 to 8 mph W | 20% |
| Tuesday | 65°F | Sunny | 6 to 12 mph W | 10% |
Forecast source: National Weather Service (api.weather.gov) for McNair (38.952, -77.414). Updated through the day.
Growing snapshot for McNair
Last spring frost
Apr 15
First fall frost
Oct 24
Growing season
194 days
Hardiness zone
7b
More local growing data for McNair: nearby ZIP 20171 weather · frost dates · planting calendar · Virginia frost dates
Nearby towns & communities
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Clifton
Crosspointe
Difficult Run
Dranesville
Dunn Loring
Fair Lakes
Fair Oaks
Fairfax
Fairfax Station
Floris
Fort Belvoir
Fort Hunt
Franconia
Franklin Farm
George Mason
Great Falls
Great Falls Crossing
Greenbriar
Groveton
Hayfield
Herndon
Climate data from the nearest NOAA station, Washington Dc Dulles Ap, Va (3.7 mi from McNair). Frost dates are 1991–2020 averages, not a forecast. Page updated Nov 4, 2026.