Flatlick Branch at Chantilly
1.9 mi- Level
- 1.1 ft
- Flow
- 18 cfs
Reading from Sat 5 AM · NWS gauge page
Observed 6:10 AM EDT at KIAD
Greenbriar, VA weather
Clear and 39°4°.
Today: low 37°3° (likely 37°3° to 40°4°), high 63°17° (likely 61°16° to 63°17°).
Now 39°4°
Clear
- Wind
- Calm
- Light through 6 PM
- Dew point
- 37°3°
- Comfortable
- Humidity
- 93%
- Air 39°4°, dew point 37°3° · fog or dew likely
- UV index
- 0Low
- Moderate 11 AM–5 PM · peak 4
- Air quality
- 48Good
- PM2.5 (fine particles) · tomorrow moderate
- Pressure
- 30.5 inHg1033 hPa
- Rising slowly · +0.03 inHg+1.0 hPa in 3 h
Next 2 hours
No precipitation expected in the next 2 hours.
From forecast models
Next 48 hours
Good hours for
This morningUp to 55°13° by 11 AM · Clear
This afternoonUp to 63°17° by 3 PM · Clear
TonightDown to 37°3° by 5 AM · Clear
Tomorrow morningUp to 56°13° by 11 AM · Clear
Tomorrow afternoonUp to 66°19° by 2 PM · Clear
Tomorrow nightDown to 40°4° by 5 AM · Clear
| Hour | Conditions | Temperature | Feels like | Precipitation | Wind | Humidity | Cloud cover | UV index |
|---|---|---|---|---|---|---|---|---|
| Sat 6a | Clear | 40°4° (likely 37°3° to 41°5°) | 40°4° | 0% | 1 mph2 km/h from NE, gusts 5 mph8 km/h | 96% | 16% | 0 |
| Sat 7a | Sunny | 38°3° (likely 37°3° to 40°4°) | 38°3° | 0% | 1 mph2 km/h from N, gusts 5 mph9 km/h | 100% | 14% | 0 |
| Sat 8a | Sunny | 38°3° (likely 37°3° to 41°5°) | 38°3° | 0% | 2 mph3 km/h from N, gusts 6 mph9 km/h | 100% | 16% | 0 |
| Sat 9a | Sunny | 44°7° (likely 42°6° to 46°8°) | 44°7° | 0% | 2 mph3 km/h from NE, gusts 6 mph10 km/h | 89% | 17% | 1 |
| Sat 10a | Sunny | 50°10° (likely 50°10° to 52°11°) | 50°10° | 0% | 2 mph3 km/h from NE, gusts 8 mph12 km/h | 74% | 0% | 2 |
| Sat 11a | Sunny | 55°13° (likely 54°12° to 56°13°) | 55°13° | 0% | 3 mph5 km/h from E, gusts 10 mph16 km/h | 64% | 1% | 3 |
| Sat 12p | Sunny | 58°14° (likely 57°14° to 59°15°) | 58°14° | 0% | 3 mph5 km/h from E, gusts 9 mph14 km/h | 55% | 10% | 4 |
| Sat 1p | Sunny | 59°15° (likely 59°15° to 61°16°) | 59°15° | 0% | 3 mph5 km/h from E, gusts 8 mph12 km/h | 51% | 13% | 4 |
| Sat 2p | Mostly sunny | 62°17° (likely 60°16° to 62°17°) | 62°17° | 0% | 3 mph5 km/h from E, gusts 7 mph12 km/h | 44% | 18% | 4 |
| Sat 3p | Mostly sunny | 63°17° (likely 61°16° to 63°17°) | 63°17° | 0% | 3 mph5 km/h from E, gusts 7 mph12 km/h | 43% | 19% | 4 |
| Sat 4p | Mostly sunny | 62°17° (likely 61°16° to 62°17°) | 62°17° | 0% | 3 mph5 km/h from E, gusts 7 mph12 km/h | 46% | 20% | 3 |
| Sat 5p | Mostly sunny | 62°17° (likely 59°15° to 62°17°) | 62°17° | 0% | 3 mph5 km/h from E, gusts 8 mph13 km/h | 46% | 33% | 1 |
| Sat 6p | Clear | 58°14° (likely 56°13° to 59°15°) | 58°14° | 0% | 3 mph5 km/h from E, gusts 7 mph12 km/h | 55% | 20% | 0 |
| Sat 7p | Partly cloudy | 53°12° (likely 53°12° to 55°13°) | 53°12° | 0% | 3 mph5 km/h from E, gusts 5 mph9 km/h | 69% | 43% | 0 |
| Sat 8p | Clear | 49°9° (likely 49°9° to 53°12°) | 48°9° | 0% | 3 mph5 km/h from E, gusts 8 mph13 km/h | 80% | 17% | 0 |
| Sat 9p | Clear | 47°8° (likely 47°8° to 51°11°) | 47°8° | 0% | 2 mph3 km/h from E, gusts 7 mph11 km/h | 86% | 0% | 0 |
| Sat 10p | Clear | 44°7° (likely 44°7° to 49°9°) | 44°7° | 0% | 2 mph3 km/h from E, gusts 7 mph11 km/h | 93% | 4% | 0 |
| Sat 11p | Clear | 43°6° (likely 43°6° to 48°9°) | 43°6° | 0% | 1 mph2 km/h from E, gusts 6 mph9 km/h | 96% | 17% | 0 |
| Sun 12a | Clear | 42°6° (likely 42°6° to 48°9°) | 42°6° | 0% | 1 mph2 km/h from E, gusts 7 mph11 km/h | 100% | 22% | 0 |
| Sun 1a | Clear | 41°5° (likely 41°5° to 47°8°) | 41°5° | 0% | 1 mph2 km/h from E, gusts 6 mph10 km/h | 100% | 14% | 0 |
| Sun 2a | Clear | 39°4° (likely 39°4° to 46°8°) | 39°4° | 0% | 1 mph2 km/h from NE, gusts 7 mph11 km/h | 100% | 13% | 0 |
| Sun 3a | Clear | 39°4° (likely 39°4° to 45°7°) | 39°4° | 0% | 0 mph0 km/h, gusts 6 mph9 km/h | 100% | 17% | 0 |
| Sun 4a | Mostly clear | 38°3° (likely 38°3° to 45°7°) | 38°3° | 0% | 0 mph0 km/h, gusts 5 mph8 km/h | 100% | 20% | 0 |
| Sun 5a | Clear | 37°3° (likely 37°3° to 45°7°) | 37°3° | 0% | 1 mph2 km/h from NE, gusts 5 mph8 km/h | 100% | 5% | 0 |
| Sun 6a | Clear | 37°3° (likely 37°3° to 43°6°) | 37°3° | 0% | 1 mph2 km/h from N, gusts 5 mph8 km/h | 100% | 7% | 0 |
| Sun 7a | Sunny | 37°3° (likely 37°3° to 42°6°) | 37°3° | 0% | 1 mph2 km/h from N, gusts 5 mph8 km/h | 100% | 14% | 0 |
| Sun 8a | Sunny | 37°3° (likely 37°3° to 42°6°) | 37°3° | 0% | 2 mph3 km/h from N, gusts 6 mph9 km/h | 100% | 22% | 0 |
| Sun 9a | Sunny | 43°6° (likely 43°6° to 47°8°) | 43°6° | 0% | 1 mph2 km/h from N, gusts 7 mph11 km/h | 96% | 24% | 1 |
| Sun 10a | Sunny | 50°10° (likely 50°10° to 53°12°) | 50°10° | 0% | 0 mph0 km/h, gusts 7 mph11 km/h | 80% | 14% | 2 |
| Sun 11a | Mostly sunny | 56°13° (likely 56°13° to 58°14°) | 56°13° | 0% | 1 mph2 km/h from N, gusts 7 mph11 km/h | 66% | 11% | 3 |
| Sun 12p | Mostly sunny | 60°16° (likely 59°15° to 62°17°) | 60°16° | 0% | 1 mph2 km/h from NE, gusts 7 mph11 km/h | 58% | 10% | 4 |
| Sun 1p | Mostly sunny | 63°17° (likely 61°16° to 63°17°) | 63°17° | 0% | 0 mph0 km/h, gusts 5 mph8 km/h | 50% | 17% | 4 |
| Sun 2p | Sunny | 66°19° (likely 62°17° to 66°19°) | 66°19° | 0% | 1 mph2 km/h from SE, gusts 6 mph9 km/h | 45% | 36% | 4 |
| Sun 3p | Sunny | 66°19° (likely 61°16° to 66°19°) | 66°19° | 0% | 1 mph2 km/h from SE, gusts 5 mph8 km/h | 43% | 16% | 4 |
| Sun 4p | Sunny | 66°19° (likely 62°17° to 66°19°) | 66°19° | 0% | 1 mph2 km/h from SE, gusts 5 mph8 km/h | 43% | 12% | 3 |
| Sun 5p | Sunny | 66°19° (likely 61°16° to 66°19°) | 66°19° | 0% | 1 mph2 km/h from SE, gusts 5 mph8 km/h | 45% | 8% | 1 |
| Sun 6p | Clear | 61°16° (likely 58°14° to 61°16°) | 61°16° | 0% | 0 mph0 km/h, gusts 4 mph6 km/h | 53% | 1% | 0 |
| Sun 7p | Clear | 56°13° (likely 55°13° to 57°14°) | 56°13° | 0% | 1 mph2 km/h from SE, gusts 3 mph4 km/h | 66% | 1% | 0 |
| Sun 8p | Clear | 53°12° (likely 52°11° to 55°13°) | 53°12° | 0% | 1 mph2 km/h from SE, gusts 3 mph5 km/h | 77% | 0% | 0 |
| Sun 9p | Clear | 49°9° (likely 49°9° to 53°12°) | 49°9° | 0% | 0 mph0 km/h, gusts 4 mph7 km/h | 89% | 0% | 0 |
| Sun 10p | Clear | 47°8° (likely 47°8° to 50°10°) | 47°8° | 0% | 0 mph0 km/h, gusts 6 mph9 km/h | 96% | 0% | 0 |
| Sun 11p | Clear | 46°8° (likely 46°8° to 49°9°) | 46°8° | 0% | 0 mph0 km/h, gusts 5 mph8 km/h | 96% | 0% | 0 |
| Mon 12a | Clear | 44°7° (likely 44°7° to 49°9°) | 44°7° | 0% | 0 mph0 km/h, gusts 5 mph8 km/h | 100% | 0% | 0 |
| Mon 1a | Clear | 43°6° (likely 43°6° to 49°9°) | 43°6° | 0% | 1 mph2 km/h from W, gusts 4 mph7 km/h | 100% | 0% | 0 |
| Mon 2a | Clear | 42°6° (likely 41°5° to 48°9°) | 42°6° | 0% | 1 mph2 km/h from W, gusts 3 mph5 km/h | 100% | 13% | 0 |
| Mon 3a | Clear | 41°5° (likely 39°4° to 50°10°) | 41°5° | 0% | 1 mph2 km/h from W, gusts 3 mph5 km/h | 100% | 16% | 0 |
| Mon 4a | Clear | 41°5° (likely 38°3° to 49°9°) | 41°5° | 0% | 2 mph3 km/h from W, gusts 3 mph5 km/h | 100% | 17% | 0 |
| Mon 5a | Clear | 40°4° (likely 37°3° to 49°9°) | 40°4° | 0% | 2 mph3 km/h from W, gusts 3 mph4 km/h | 100% | 16% | 0 |
Days ahead
Shaded: typical range for these dates (1991–2020)
Today, Oct 24. Fog. High 63°17°, low 37°3°. Typical 65°18° / 42°6°. Dry. Forecasts agree.
Morning
6 AM–noon
Sunny, 38°3°Dry
Afternoon
noon–6 PM
Mostly sunny, 63°17°Dry
Evening
6 PM–midnight
Clear, 49°9°Dry
Overnight
midnight–6 AM
Clear, 37°3°Dry
Official NWS forecast
Today: Patchy fog between 7am and 8am. Sunny, with a high near 63. Northeast wind around 3 mph.
Tonight: Patchy fog between 11pm and 5am, then patchy frost and patchy fog. Mostly clear, with a low around 37. Northeast wind 0 to 3 mph.
Forecasts agreeIndependent forecasts are close; the range is narrow.
- High, likely
- 61°16°–63°17°
- Low, likely
- 37°3°–40°4°
- Typical high / low
- 65°18° / 42°6°
- Wind
- 6 mph10 km/h, gusts 13 mph21 km/h
- UV peak
- 4
Tomorrow, Oct 25. Fog. High 66°19°, low 37°3°. Typical 64°18° / 42°6°. Dry. Mostly agree.
Morning
6 AM–noon
Sunny, 37°3°Dry
Afternoon
noon–6 PM
Sunny, 66°19°Dry
Evening
6 PM–midnight
Clear, 53°12°Dry
Overnight
midnight–6 AM
Clear, 40°4°Dry
Official NWS forecast
Day: Patchy frost and patchy fog before 10am. Sunny, with a high near 66. Northeast wind around 2 mph.
Night: Clear, with a low around 37. Southwest wind around 2 mph.
Mostly agreeIndependent forecasts are fairly close; small surprises are possible.
- High, likely
- 62°17°–66°19°
- Low, likely
- 37°3°–42°6°
- Typical high / low
- 64°18° / 42°6°
- Wind
- 6 mph10 km/h
- UV peak
- 4
Monday, Oct 26. Mostly sunny. High 69°21°, low 48°9°. Typical 64°18° / 41°5°. Dry. Forecasts agree.
Morning
6 AM–noon
Sunny, 41°5°Dry
Afternoon
noon–6 PM
Sunny, 68°20°Dry
Evening
6 PM–midnight
Clear, 56°13°Dry
Overnight
midnight–6 AM
Clear, 49°10°Dry
Hours this far out come from computer models only.
Official NWS forecast
Day: Patchy frost between 7am and 8am. Sunny, with a high near 69. West wind around 5 mph.
Night: Mostly clear, with a low around 48.
Forecasts agreeIndependent forecasts are close; the range is narrow.
- High, likely
- 68°20°–69°21°
- Low, likely
- 35°2°–48°9°
- Typical high / low
- 64°18° / 41°5°
- Wind
- 7 mph11 km/h, gusts 14 mph22 km/h
- UV peak
- 4
Tuesday, Oct 27. Mostly sunny. High 67°19°, low 45°7°. Typical 64°18° / 41°5°. Dry. Forecasts differ.
Morning
6 AM–noon
Sunny, 48°9°Dry
Afternoon
noon–6 PM
Sunny, 67°19°Dry
Evening
6 PM–midnight
Clear, 57°14°Dry
Overnight
midnight–6 AM
Clear, 47°8°Dry
Hours this far out come from computer models only.
Official NWS forecast
Day: Sunny, with a high near 67.
Night: Mostly clear, with a low around 45.
Forecasts differIndependent forecasts disagree; expect changes and plan for the range.
- High, likely
- 65°18°–70°21°
- Low, likely
- 44°7°–51°11°
- Typical high / low
- 64°18° / 41°5°
- Wind
- 9 mph15 km/h, gusts 24 mph39 km/h
- UV peak
- 4
Wednesday, Oct 28. Cloudy. High 64°18°, low 47°8°. Typical 64°18° / 41°5°. Dry. Forecasts differ.
Morning
6 AM–noon
Mostly sunny, 47°8°Dry
Afternoon
noon–6 PM
Partly sunny, 64°18°Dry
Evening
6 PM–midnight
Partly cloudy, 54°12°Dry
Overnight
midnight–6 AM
Clear, 47°8°Dry
Hours this far out come from computer models only.
Official NWS forecast
Day: Partly sunny, with a high near 64.
Night: Mostly cloudy, with a low around 47.
Forecasts differIndependent forecasts disagree; expect changes and plan for the range.
- High, likely
- 61°16°–66°19°
- Low, likely
- 43°6°–48°9°
- Typical high / low
- 64°18° / 41°5°
- Wind
- 6 mph10 km/h, gusts 16 mph25 km/h
- UV peak
- 4
Thursday, Oct 29. Partly sunny. High 70°21°, low 49°9°. Typical 63°17° / 40°4°. Dry. Mostly agree.
Morning
6 AM–noon
Partly sunny, 47°8°Dry
Afternoon
noon–6 PM
Sunny, 67°19°Dry
Evening
6 PM–midnight
Clear, 57°14°Dry
Overnight
midnight–6 AM
Clear, 48°9°Dry
Hours this far out come from computer models only.
Official NWS forecast
Day: Mostly sunny, with a high near 70.
Night: Mostly clear, with a low around 49.
Mostly agreeIndependent forecasts are fairly close; small surprises are possible.
- High, likely
- 65°18°–70°21°
- Low, likely
- 45°7°–49°9°
- Typical high / low
- 63°17° / 40°4°
- Wind
- 7 mph11 km/h, gusts 23 mph37 km/h
- UV peak
- 4
Friday, Oct 30. Mostly sunny. High 72°22°, low 48°9°. Typical 63°17° / 40°4°. Dry. Forecasts agree.
Morning
6 AM–noon
Sunny, 46°8°Dry
Afternoon
noon–6 PM
Sunny, 73°23°Dry
Evening
6 PM–midnight
Clear, 61°16°Dry
Overnight
midnight–6 AM
Clear, 50°10°Dry
Hours this far out come from computer models only.
Official NWS forecast
Day: Sunny, with a high near 72.
Night: Mostly clear, with a low around 48.
Forecasts agreeIndependent forecasts are close; the range is narrow.
- High, likely
- 72°22°–75°24°
- Low, likely
- 43°6°–49°9°
- Typical high / low
- 63°17° / 40°4°
- Wind
- 7 mph11 km/h, gusts 21 mph33 km/h
- UV peak
- 4
Saturday, Oct 31. Cloudy. High 71°22°, low 49°9°. Typical 62°17° / 40°4°. Dry. Forecasts differ.
Morning
6 AM–noon
Partly sunny, 49°9°Dry
Afternoon
noon–6 PM
Cloudy, 71°22°Dry
Evening
6 PM–midnight
Cloudy, 61°16°Dry
Overnight
midnight–6 AM
Cloudy, 53°12°Dry
Hours this far out come from computer models only.
The National Weather Service writes about seven days ahead; this day is our model forecast only.
Forecasts differIndependent forecasts disagree; expect changes and plan for the range.
- High, likely
- 66°19°–74°23°
- Low, likely
- 43°6°–56°13°
- Typical high / low
- 62°17° / 40°4°
- Wind
- 8 mph12 km/h, gusts 22 mph35 km/h
- UV peak
- 3
Sunday, Nov 1. Cloudy. High 69°21°, low 52°11°. Typical 62°17° / 40°4°. Dry. Forecasts differ.
Morning
6 AM–noon
Cloudy, 52°11°Dry
Afternoon
noon–6 PM
Cloudy, 69°21°Dry
Evening
6 PM–midnight
Cloudy, 62°17°Dry
Overnight
midnight–6 AM
Cloudy, 58°15°Dry
Hours this far out come from computer models only.
The National Weather Service writes about seven days ahead; this day is our model forecast only.
Forecasts differIndependent forecasts disagree; expect changes and plan for the range.
- High, likely
- 63°17°–73°23°
- Low, likely
- 51°11°–53°12°
- Typical high / low
- 62°17° / 40°4°
- Wind
- 10 mph16 km/h, gusts 24 mph38 km/h
- UV peak
- 3
Monday, Nov 2. Cloudy. High 72°22°, low 58°14°. Typical 62°17° / 39°4°. Rain 0.04 in1 mm, 20% chance. Forecasts differ.
Morning
6 AM–noon
Cloudy, 61°16°Dry
Afternoon
noon–6 PM
Cloudy, 72°22°Dry
Evening
6 PM–midnight
Cloudy, 64°18°20% chance
Hours this far out come from computer models only.
The National Weather Service writes about seven days ahead; this day is our model forecast only.
Forecasts differIndependent forecasts disagree; expect changes and plan for the range.
- High, likely
- 66°19°–76°24°
- Low, likely
- 58°14°–59°15°
- Typical high / low
- 62°17° / 39°4°
- Wind
- 8 mph12 km/h, gusts 20 mph32 km/h
- UV peak
- 2
The outlook
Today
Dry, high 63°, low 37°.
Tomorrow
Dry, high 66°, low 37°, warming up.
Monday
Dry, high 69°, low 48°, warming up.
Rest of week
Mostly dry, highs 64–72°.
Want the meteorologists’ reasoning? Read the NWS forecast discussion (LWX) (opens in a new tab)
What changed since yesterday
No meaningful changes from yesterday’s forecast.
Radar
Radar data: NOAA MRMS, rendered by forecast.blue
Radar loads when scrolled into view
Rivers
NOAA river gauges within 25 mi
Below flood stage
Willow Springs Branch near Centreville (Hampton Forest Sec 4 Regional Pond)
2.4 mi- Level
- 367 ft
Reading from Sat 12:25 AM · NWS gauge page
Unnamed Tributary near Fairfax Center
3.0 mi- Level
- 383 ft
Reading from Sat 1:05 AM · NWS gauge page
Horsepen Run above Oak Hill (West Ox Road Regional Pond)
3.8 mi- Level
- 322 ft
Reading from Sat 12:45 AM · NWS gauge page
For your home
What this week’s weather means for heating, cooling, pipes and fresh air.
Heating this week
About 66% less heating than a typical week.
This week 30Typical 88
Heating degree days, base 65°F
Heat-pump hours, next 7 days
- h below 47°F
- 24
- h below 17°F
- 0
- h below 5°F
- 0
47, 17 and 5°F are the test points heat pumps are rated at. About 15 hours are near freezing and damp, when outdoor units defrost more often.
Comfort
Dry air outside (dew point 37°F).
Open the windows?
Today, 2:00 PM–5:00 PM
Good stretch to open the windows.
Is this typical?
Washington Dulles International Airport · official normals 1991–2020 · records 1960–2026
Oct 24, today vs a typical year
Today’s expected high is 2°1° colder than typical.
- Normal high / low
- 65°18° / 42°6°
- Forecast high / low
- 63°17° / 37°3°
- Record high
- 84°29° in 2001
- Record low
- 15°−9° in 1969
Last 7 days vs normal
On average 2°1° colder than normal (daily mean temperature).
- −6°−3°SunOct 18
- −3°−2°MonOct 19
- +2°+1°TueOct 20
- ±0°WedOct 21
- −2°−1°ThuOct 22
- —FriOct 23
- —SatOct 24
Greenbriar weather by month: normals, records, snow and freeze dates
Sun & moon
Sun
Sunrise 7:28 AM, sunset 6:18 PM.
- Daylight
- 10 h 50 min
- Losing 2 min 25 s a day; shortest Dec 21, 1 h 24 min less
- Golden hour
- 5:41–6:35 PM
- Morning 7:11–8:05 AM
- Blue hour
- 6:35–6:45 PM
- Morning 7:01–7:11 AM; first light 7:01 AM
Stars tonight? Good
Mostly clear 6:48–7:01 AM; moon 96% lit but below the horizon.
Moon
Waxing gibbous
96% lit · growing
- Today
- sets 5:40 AM · rises 5:15 PM
- Full moon
- Oct 26
- New moon
- Nov 9
