Observed 9:30 AM EDT at KIAD

Great Falls, VA weather

Sunny and 46°8°, jacket by 7 PM.

Mostly agree

Now 46°8°

Sunny

Wind: 5 mph7 km/h; From the north-northwest. Up to 5 mph8 km/h through 10 PM
Dew point: 43°6°; Comfortable
UV index: 1Low; Moderate 12–3 PM · peak 4
Air quality: 54Moderate; Main pollutant: PM2.5 (fine particles)
Pressure: 30.56 inHg1035 hPa; Rising slowly · +0.04 inHg+1.2 hPa in 3 h

No precipitation expected in the next 2 hours.

From forecast models

Next 48 hours

Good hours for

High 63°17° today at 3 PM
Below 50°10° tonight after 9 PM
Low 37°3° tomorrow at 7 AM
Above 50°10° tomorrow by 10 AM

This morningUp to 56°13° by 11 AM · Clear
This afternoonUp to 63°17° by 3 PM · Clear
TonightDown to 38°3° by 5 AM · Clear
Tomorrow morningUp to 57°14° by 11 AM · Clear
Tomorrow afternoonUp to 66°19° by 3 PM · Clear
Tomorrow nightDown to 41°5° by 5 AM · Clear
Monday morningUp to 44°7° by 9 AM · Partly cloudy

Hourly forecast, next 48 hours, in the place's local time
Hour	Conditions	Temperature	Feels like	Precipitation	Wind	Humidity	Cloud cover	UV index
Sat 10a	Mostly sunny	50°10° (likely 49°9° to 51°11°)	50°10°	0%	2 mph3 km/h from NE, gusts 3 mph5 km/h	71%	15%	1
Sat 11a	Sunny	56°13° (likely 54°12° to 56°13°)	56°13°	0%	3 mph5 km/h from E, gusts 10 mph16 km/h	59%	1%	2
Sat 12p	Sunny	58°14° (likely 57°14° to 59°15°)	58°14°	0%	3 mph5 km/h from E, gusts 10 mph16 km/h	53%	8%	3
Sat 1p	Sunny	61°16° (likely 59°15° to 61°16°)	61°16°	0%	3 mph5 km/h from SE, gusts 9 mph15 km/h	48%	18%	4
Sat 2p	Sunny	62°17° (likely 59°15° to 62°17°)	62°17°	0%	3 mph5 km/h from E, gusts 8 mph13 km/h	44%	13%	3
Sat 3p	Sunny	63°17° (likely 60°16° to 63°17°)	63°17°	0%	3 mph5 km/h from E, gusts 8 mph13 km/h	43%	17%	2
Sat 4p	Mostly sunny	62°17° (likely 59°15° to 62°17°)	62°17°	0%	5 mph8 km/h from E, gusts 7 mph11 km/h	44%	29%	1
Sat 5p	Partly sunny	62°17° (likely 58°14° to 62°17°)	62°17°	0%	5 mph8 km/h from E, gusts 8 mph12 km/h	44%	36%	1
Sat 6p	Mostly clear	58°14° (likely 55°13° to 59°15°)	58°14°	0%	3 mph5 km/h from E, gusts 7 mph11 km/h	53%	26%	0
Sat 7p	Mostly clear	54°12° (likely 51°11° to 55°13°)	54°12°	0%	3 mph5 km/h from E, gusts 7 mph11 km/h	61%	24%	0
Sat 8p	Clear	50°10° (likely 48°9° to 51°11°)	49°9°	0%	3 mph5 km/h from E, gusts 8 mph13 km/h	74%	9%	0
Sat 9p	Clear	48°9° (likely 47°8° to 50°10°)	48°9°	0%	2 mph3 km/h from E, gusts 7 mph11 km/h	77%	1%	0
Sat 10p	Clear	45°7° (likely 45°7° to 48°9°)	45°7°	0%	1 mph2 km/h from E, gusts 6 mph9 km/h	86%	1%	0
Sat 11p	Clear	44°7° (likely 44°7° to 48°9°)	44°7°	0%	1 mph2 km/h from E, gusts 5 mph8 km/h	86%	12%	0
Sun 12a	Clear	43°6° (likely 43°6° to 47°8°)	43°6°	0%	1 mph2 km/h from E, gusts 5 mph9 km/h	93%	22%	0
Sun 1a	Clear	42°6° (likely 42°6° to 46°8°)	42°6°	0%	0 mph0 km/h, gusts 5 mph9 km/h	96%	14%	0
Sun 2a	Clear	42°6° (likely 42°6° to 45°7°)	42°6°	0%	0 mph0 km/h, gusts 6 mph9 km/h	96%	12%	0
Sun 3a	Clear	41°5° (likely 41°5° to 45°7°)	41°5°	0%	0 mph0 km/h, gusts 5 mph8 km/h	100%	10%	0
Sun 4a	Clear	39°4° (likely 39°4° to 44°7°)	39°4°	0%	0 mph0 km/h, gusts 5 mph7 km/h	100%	3%	0
Sun 5a	Clear	38°3° (likely 38°3° to 43°6°)	38°3°	0%	0 mph0 km/h, gusts 2 mph3 km/h	100%	4%	0
Sun 6a	Clear	38°3° (likely 38°3° to 42°6°)	38°3°	0%	0 mph0 km/h, gusts 3 mph4 km/h	100%	3%	0
Sun 7a	Sunny	37°3° (likely 37°3° to 41°5°)	37°3°	0%	0 mph0 km/h, gusts 3 mph4 km/h	100%	8%	0
Sun 8a	Sunny	38°3° (likely 37°3° to 42°6°)	38°3°	0%	1 mph2 km/h from N, gusts 2 mph4 km/h	100%	15%	0
Sun 9a	Mostly sunny	44°7° (likely 42°6° to 46°8°)	44°7°	0%	1 mph2 km/h from N, gusts 3 mph4 km/h	89%	21%	1
Sun 10a	Sunny	51°11° (likely 51°11° to 53°12°)	51°11°	0%	1 mph2 km/h from N, gusts 6 mph10 km/h	74%	4%	2
Sun 11a	Sunny	57°14° (likely 57°14° to 58°14°)	57°14°	0%	1 mph2 km/h from N, gusts 5 mph8 km/h	62%	4%	3
Sun 12p	Sunny	60°16° (likely 60°16° to 61°16°)	60°16°	0%	1 mph2 km/h from E, gusts 5 mph8 km/h	55%	5%	4
Sun 1p	Sunny	63°17° (likely 62°17° to 63°17°)	63°17°	0%	1 mph2 km/h from SE, gusts 4 mph7 km/h	50%	6%	4
Sun 2p	Mostly sunny	65°18° (likely 63°17° to 65°18°)	65°18°	0%	1 mph2 km/h from S, gusts 4 mph7 km/h	45%	8%	4
Sun 3p	Sunny	66°19° (likely 64°18° to 66°19°)	66°19°	0%	1 mph2 km/h from SE, gusts 5 mph8 km/h	43%	6%	4
Sun 4p	Sunny	65°18° (likely 63°17° to 65°18°)	65°18°	0%	1 mph2 km/h from SE, gusts 5 mph8 km/h	43%	10%	3
Sun 5p	Sunny	65°18° (likely 62°17° to 65°18°)	65°18°	0%	1 mph2 km/h from SE, gusts 5 mph8 km/h	43%	8%	1
Sun 6p	Clear	62°17° (likely 58°14° to 62°17°)	62°17°	0%	1 mph2 km/h from SE, gusts 5 mph8 km/h	50%	2%	0
Sun 7p	Clear	56°13° (likely 54°12° to 56°13°)	56°13°	0%	0 mph0 km/h, gusts 5 mph7 km/h	64%	7%	0
Sun 8p	Clear	53°12° (likely 51°11° to 55°13°)	53°12°	0%	1 mph2 km/h from SE, gusts 5 mph7 km/h	74%	1%	0
Sun 9p	Clear	51°11° (likely 49°9° to 53°12°)	51°11°	0%	0 mph0 km/h, gusts 5 mph8 km/h	80%	0%	0
Sun 10p	Clear	48°9° (likely 48°9° to 50°10°)	48°9°	0%	0 mph0 km/h, gusts 5 mph7 km/h	86%	0%	0
Sun 11p	Clear	46°8° (likely 46°8° to 48°9°)	46°8°	0%	0 mph0 km/h, gusts 4 mph6 km/h	93%	0%	0
Mon 12a	Clear	45°7° (likely 45°7° to 47°8°)	45°7°	0%	0 mph0 km/h, gusts 4 mph6 km/h	96%	0%	0
Mon 1a	Clear	44°7° (likely 42°6° to 46°8°)	44°7°	0%	1 mph2 km/h from W, gusts 3 mph5 km/h	100%	0%	0
Mon 2a	Clear	43°6° (likely 40°4° to 45°7°)	43°6°	0%	1 mph2 km/h from W, gusts 3 mph5 km/h	100%	6%	0
Mon 3a	Clear	42°6° (likely 38°3° to 45°7°)	42°6°	0%	1 mph2 km/h from W, gusts 3 mph5 km/h	100%	13%	0
Mon 4a	Clear	42°6° (likely 38°3° to 44°7°)	42°6°	0%	1 mph2 km/h from W, gusts 4 mph7 km/h	100%	17%	0
Mon 5a	Mostly clear	41°5° (likely 38°3° to 43°6°)	41°5°	0%	1 mph2 km/h from W, gusts 5 mph8 km/h	100%	22%	0
Mon 6a	Mostly clear	39°4° (likely 37°3° to 43°6°)	39°4°	0%	1 mph2 km/h from W, gusts 5 mph7 km/h	100%	25%	0
Mon 7a	Sunny	38°3° (likely 36°2° to 42°6°)	38°3°	0%	2 mph3 km/h from W, gusts 5 mph7 km/h	100%	29%	0
Mon 8a	Mostly sunny	39°4° (likely 34°1° to 43°6°)	39°4°	0%	2 mph3 km/h from W, gusts 5 mph8 km/h	100%	36%	0
Mon 9a	Mostly sunny	44°7° (likely 39°4° to 49°9°)	44°7°	0%	2 mph3 km/h from W, gusts 5 mph8 km/h	93%	31%	1

Days ahead

Shaded: typical range for these dates (1991–2020)

Today, Oct 24. Mostly sunny. High 63°17°, low 37°3°. Typical 65°18° / 42°6°. Dry. Mostly agree.
1. Morning
  6 AM–noon
  Sunny, 56°13°
  Dry
2. Afternoon
  noon–6 PM
  Sunny, 63°17°
  Dry
3. Evening
  6 PM–midnight
  Clear, 50°10°
  Dry
4. Overnight
  midnight–6 AM
  Clear, 38°3°
  Dry
Official NWS forecast
Today: Sunny, with a high near 63. East wind around 5 mph.
Tonight: Patchy fog after 1am. Mostly clear, with a low around 37. East wind 0 to 3 mph.
Mostly agreeIndependent forecasts are fairly close; small surprises are possible.
High, likely
60°16°–63°17°
Low, likely
36°2°–39°4°
Typical high / low
65°18° / 42°6°
Wind
6 mph9 km/h, gusts 13 mph22 km/h
UV peak
4
Tomorrow, Oct 25. Fog. High 66°19°, low 38°3°. Typical 64°18° / 42°6°. Dry. Forecasts agree.
1. Morning
  6 AM–noon
  Mostly sunny, 38°3°
  Dry
2. Afternoon
  noon–6 PM
  Sunny, 66°19°
  Dry
3. Evening
  6 PM–midnight
  Clear, 53°12°
  Dry
4. Overnight
  midnight–6 AM
  Clear, 41°5°
  Dry
Official NWS forecast
Day: Patchy fog before 7am, then patchy frost and patchy fog between 7am and 9am. Sunny, with a high near 66. Northeast wind around 1 mph.
Night: Clear, with a low around 38. West wind around 1 mph.
Forecasts agreeIndependent forecasts are close; the range is narrow.
High, likely
64°18°–66°19°
Low, likely
37°3°–41°5°
Typical high / low
64°18° / 42°6°
Wind
5 mph9 km/h
UV peak
4
Monday, Oct 26. Mostly sunny. High 69°21°, low 47°8°. Typical 64°18° / 41°5°. Dry. Forecasts agree.
1. Morning
  6 AM–noon
  Mostly sunny, 39°4°
  Dry
2. Afternoon
  noon–6 PM
  Sunny, 67°20°
  Dry
3. Evening
  6 PM–midnight
  Clear, 54°12°
  Dry
4. Overnight
  midnight–6 AM
  Clear, 48°9°
  Dry
Hours this far out come from computer models only.
Official NWS forecast
Day: Sunny, with a high near 69. Northwest wind 1 to 6 mph.
Night: Mostly clear, with a low around 47.
Forecasts agreeIndependent forecasts are close; the range is narrow.
High, likely
67°19°–69°21°
Low, likely
34°1°–47°8°
Typical high / low
64°18° / 41°5°
Wind
8 mph12 km/h, gusts 14 mph23 km/h
UV peak
4
Tuesday, Oct 27. Mostly sunny. High 66°19°, low 45°7°. Typical 64°18° / 41°5°. Dry. Forecasts differ.
1. Morning
  6 AM–noon
  Sunny, 46°8°
  Dry
2. Afternoon
  noon–6 PM
  Sunny, 66°19°
  Dry
3. Evening
  6 PM–midnight
  Clear, 54°12°
  Dry
4. Overnight
  midnight–6 AM
  Cloudy, 45°7°
  Dry
Hours this far out come from computer models only.
Official NWS forecast
Day: Sunny, with a high near 66.
Night: Mostly clear, with a low around 45.
Forecasts differIndependent forecasts disagree; expect changes and plan for the range.
High, likely
64°18°–70°21°
Low, likely
43°6°–49°9°
Typical high / low
64°18° / 41°5°
Wind
8 mph13 km/h, gusts 19 mph30 km/h
UV peak
4
Wednesday, Oct 28. Mostly cloudy. High 64°18°, low 47°8°. Typical 64°18° / 41°5°. Dry. Mostly agree.
1. Morning
  6 AM–noon
  Mostly sunny, 45°7°
  Dry
2. Afternoon
  noon–6 PM
  Cloudy, 64°18°
  Dry
3. Evening
  6 PM–midnight
  Cloudy, 55°13°
  Dry
4. Overnight
  midnight–6 AM
  Mostly 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.
Mostly agreeIndependent forecasts are fairly close; small surprises are possible.
High, likely
63°17°–66°19°
Low, likely
41°5°–47°8°
Typical high / low
64°18° / 41°5°
Wind
7 mph12 km/h, gusts 17 mph28 km/h
UV peak
4
Thursday, Oct 29. Partly sunny. High 69°21°, low 49°9°. Typical 63°17° / 40°4°. Dry. Mostly agree.
1. Morning
  6 AM–noon
  Sunny, 47°8°
  Dry
2. Afternoon
  noon–6 PM
  Sunny, 67°20°
  Dry
3. Evening
  6 PM–midnight
  Clear, 56°13°
  Dry
4. 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 69.
Night: Mostly clear, with a low around 49.
Mostly agreeIndependent forecasts are fairly close; small surprises are possible.
High, likely
66°19°–69°21°
Low, likely
45°7°–49°9°
Typical high / low
63°17° / 40°4°
Wind
7 mph11 km/h, gusts 22 mph36 km/h
UV peak
4
Friday, Oct 30. Mostly sunny. High 72°22°, low 49°9°. Typical 63°17° / 40°4°. Dry. Forecasts agree.
1. Morning
  6 AM–noon
  Sunny, 47°8°
  Dry
2. Afternoon
  noon–6 PM
  Sunny, 73°23°
  Dry
3. Evening
  6 PM–midnight
  Clear, 60°15°
  Dry
4. 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 72.
Night: Mostly clear, with a low around 49.
Forecasts agreeIndependent forecasts are close; the range is narrow.
High, likely
72°22°–74°23°
Low, likely
43°6°–49°9°
Typical high / low
63°17° / 40°4°
Wind
10 mph16 km/h, gusts 26 mph41 km/h
UV peak
4
Saturday, Oct 31. Cloudy. High 69°21°, low 47°8°. Typical 62°17° / 40°4°. Dry. Forecasts differ.
1. Morning
  6 AM–noon
  Sunny, 46°8°
  Dry
2. Afternoon
  noon–6 PM
  Cloudy, 68°20°
  Dry
3. Evening
  6 PM–midnight
  Cloudy, 59°15°
  Dry
4. Overnight
  midnight–6 AM
  Cloudy, 51°10°
  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
60°16°–74°23°
Low, likely
43°6°–51°11°
Typical high / low
62°17° / 40°4°
Wind
10 mph17 km/h, gusts 27 mph44 km/h
UV peak
3
Sunday, Nov 1. Cloudy. High 67°19°, low 50°10°. Typical 62°17° / 40°4°. Rain 0.02 in0.5 mm, 20% chance. Forecasts differ.
1. Morning
  6 AM–noon
  Cloudy, 50°10°
  Dry
2. Afternoon
  noon–6 PM
  Cloudy, 66°19°
  Dry
3. Evening
  6 PM–midnight
  Cloudy, 58°15°
  20% chance
4. Overnight
  midnight–6 AM
  Cloudy, 54°12°
  20% chance · 0.02 in0.4 mm
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
56°13°–72°22°
Low, likely
42°6°–55°13°
Typical high / low
62°17° / 40°4°
Wind
8 mph13 km/h, gusts 21 mph34 km/h
UV peak
3
Monday, Nov 2. Cloudy. High 67°19°, low 54°12°. Typical 62°17° / 39°4°. Rain 0.09 in2.3 mm, 20% chance. Forecasts differ.
1. Morning
  6 AM–noon
  Cloudy, 58°14°
  Dry
2. Afternoon
  noon–6 PM
  Cloudy, 68°20°
  Dry
3. Evening
  6 PM–midnight
  Cloudy, 59°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
56°13°–75°24°
Low, likely
44°7°–59°15°
Typical high / low
62°17° / 39°4°
Wind
8 mph13 km/h, gusts 16 mph25 km/h
UV peak
1

10 days15 days30 days

The outlook

Today
Dry, high 63°, low 37°.
Tomorrow
Dry, high 66°, low 38°, warming up.
Monday
Dry, high 69°, low 47°, 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

Full-screen radar

Rivers

NOAA river gauges within 25 mi

Seneca Creek at Dawsonville

8.2 mi

Below flood stage

Level: 1.9 ft
Flow: 44 cfs

Forecast peak 2.0 ft Sat 2 PM

Reading from Sat 8:50 AM · NWS gauge page

Potomac River near Washington DC (Little Falls)

10 mi

Below flood stage

Level: 3.1 ft
Flow: 3,510 cfs

Forecast peak 3.0 ft Sat 2 PM

Reading from Sat 8:50 AM · NWS gauge page

Piney Run at Reston (Northern Sector Pond 1)

2.5 mi

Level: 345 ft

Reading from Sat 4:55 AM · NWS gauge page

Colvin Run at Lake Fairfax near Reston

3.4 mi

Level: 262 ft

Reading from Sat 5:15 AM · NWS gauge page

For your home

What this week’s weather means for heating, cooling, pipes and fresh air.

Heating this week

About 67% less heating than a typical week.

This week 29Typical 88

Heating degree days, base 65°F

Heat-pump hours, next 7 days

h below 47°F: 23
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 14 hours are near freezing and damp, when outdoor units defrost more often.

Comfort

Dry air outside (dew point 43°F).

Open the windows?

Today, 1:00 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.

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
−1°FriOct 23
—SatOct 24

Great Falls weather by month: normals, records, snow and freeze dates

Sun & moon

Sun

Daylight: 10 h 50 min; Losing 2 min 16 s a day; shortest Dec 21, 1 h 24 min less
Golden hour: 5:41–6:34 PM; Morning 7:11–8:05 AM
Blue hour: 6:34–6:45 PM; Morning 7:00–7:11 AM; first light 7:00 AM

Stars tonight? Fair

Mostly clear 7 PM–7:01 AM, but the moon is 99% lit and up.

Moon

Waxing gibbous

97% lit · growing

Today: sets 5:40 AM · rises 5:14 PM
Full moon: Oct 26
New moon: Nov 9

Looking west from Great Falls. The highest point on the skyline is about 3,300 ft, 50 mi away.Skyline from USGS elevation data, heights drawn up to 6× taller. Sky, sun and moon as they are now.