Frost Advisory
Starts in 5 h 15 min
When
From 1 AM to 9 AM EDT Sunday.
Where
Portions of central, northeast, and northern Maryland and northern Virginia.
Issued for this forecast zone · National Weather Service Baltimore MD/Washington DC
What, impacts and precautionsHide details
What
Temperatures as low as 33 will result in frost formation.
Impacts
Frost could harm sensitive outdoor vegetation. Sensitive outdoor plants may be killed if left uncovered.
Precautionary actions
Take steps now to protect tender plants from the cold.
Areas: Frederick; Carroll; Northern Baltimore; Cecil; Northwest Montgomery; Northwest Howard; Northwest Harford; Southeast Harford; Rappahannock; Culpeper; Northern Fauquier; Southern Fauquier; Western Loudoun; Eastern Loudoun; Northwest Prince William; Central and Southeast Prince William/Manassas/Manassas Park
See it on weather.gov (opens in a new tab)

Observed 7:20 PM EDT at KIAD

Cascades, VA weather

Clear and 55°13°.

Forecasts agree

Now 55°13°

Clear

Wind: 7 mph11 km/h; From the southeast. Up to 7 mph11 km/h through 7 AM
Dew point: 41°5°; Comfortable
UV tomorrow: 4Moderate; Moderate 11 AM–5 PM · peak 4
Air quality: 31Good; Ozone · tomorrow moderate
Pressure: 30.53 inHg1034 hPa; Rising slowly · +0.02 inHg+0.7 hPa in 3 h

No precipitation expected in the next 2 hours.

From forecast models

Next 48 hours

3°2° cooler than this time yesterday (55°13° then, 52°11° now)

Good hours for

Below 50°10° tonight after 9 PM
Low 38°3° tomorrow at 7 AM
Above 50°10° tomorrow by 11 AM
High 64°18° tomorrow at 3 PM

TonightDown to 39°4° by 5 AM · Clear
Tomorrow morningUp to 55°13° by 11 AM · Clear
Tomorrow afternoonUp to 64°18° by 3 PM · Clear
Tomorrow nightDown to 39°4° by 5 AM · Clear
Monday morningUp to 56°13° by 11 AM · Clear
Monday afternoonUp to 69°21° by 3 PM · Clear

Hourly forecast, next 48 hours, in the place's local time
Hour	Conditions	Temperature	Feels like	Precipitation	Wind	Humidity	Cloud cover	UV index
Sat 7p	Mostly clear	55°13° (likely 54°12° to 56°13°)	55°13°	0%	3 mph5 km/h from E, gusts 5 mph8 km/h	55%	37%	0
Sat 8p	Clear	51°11° (likely 51°11° to 54°12°)	51°11°	0%	3 mph5 km/h from SE, gusts 8 mph12 km/h	68%	21%	0
Sat 9p	Clear	48°9° (likely 48°9° to 52°11°)	47°8°	0%	3 mph5 km/h from SE, gusts 8 mph13 km/h	80%	11%	0
Sat 10p	Clear	46°8° (likely 46°8° to 50°10°)	46°8°	0%	2 mph3 km/h from E, gusts 7 mph11 km/h	86%	0%	0
Sat 11p	Clear	45°7° (likely 45°7° to 49°9°)	45°7°	0%	2 mph3 km/h from E, gusts 5 mph8 km/h	89%	12%	0
Sun 12a	Clear	44°7° (likely 44°7° to 47°8°)	44°7°	0%	2 mph3 km/h from E, gusts 7 mph11 km/h	89%	16%	0
Sun 1a	Clear	43°6° (likely 43°6° to 46°8°)	43°6°	0%	1 mph2 km/h from S, gusts 3 mph4 km/h	93%	16%	0
Sun 2a	Clear	41°5° (likely 41°5° to 46°8°)	41°5°	0%	1 mph2 km/h from SW, gusts 2 mph4 km/h	92%	14%	0
Sun 3a	Clear	41°5° (likely 41°5° to 45°7°)	41°5°	0%	1 mph2 km/h from SW, gusts 2 mph3 km/h	92%	8%	0
Sun 4a	Clear	40°4° (likely 40°4° to 43°6°)	40°4°	0%	1 mph2 km/h from SW, gusts 3 mph4 km/h	96%	6%	0
Sun 5a	Clear	39°4° (likely 39°4° to 42°6°)	39°4°	0%	1 mph2 km/h from SW, gusts 3 mph5 km/h	96%	9%	0
Sun 6a	Clear	39°4° (likely 39°4° to 42°6°)	39°4°	0%	1 mph2 km/h from W, gusts 3 mph5 km/h	96%	12%	0
Sun 7a	Sunny	38°3° (likely 38°3° to 41°5°)	38°3°	0%	1 mph2 km/h from E, gusts 3 mph6 km/h	96%	21%	0
Sun 8a	Mostly sunny	38°3° (likely 38°3° to 41°5°)	38°3°	0%	1 mph2 km/h from W, gusts 2 mph4 km/h	96%	44%	0
Sun 9a	Sunny	43°6° (likely 43°6° to 46°8°)	43°6°	0%	1 mph2 km/h from S, gusts 2 mph3 km/h	93%	21%	1
Sun 10a	Sunny	49°9° (likely 49°9° to 52°11°)	49°9°	0%	1 mph2 km/h from S, gusts 4 mph7 km/h	80%	3%	2
Sun 11a	Sunny	55°13° (likely 55°13° to 58°14°)	55°13°	0%	1 mph2 km/h from S, gusts 5 mph8 km/h	69%	5%	3
Sun 12p	Sunny	58°14° (likely 58°14° to 61°16°)	58°14°	0%	1 mph2 km/h from SE, gusts 6 mph10 km/h	62%	8%	4
Sun 1p	Sunny	61°16° (likely 61°16° to 64°18°)	61°16°	0%	1 mph2 km/h from S, gusts 5 mph8 km/h	56%	9%	4
Sun 2p	Mostly sunny	63°17° (likely 63°17° to 65°18°)	63°17°	0%	2 mph3 km/h from S, gusts 5 mph9 km/h	50%	13%	4
Sun 3p	Mostly sunny	64°18° (likely 64°18° to 66°19°)	64°18°	0%	2 mph3 km/h from S, gusts 7 mph11 km/h	48%	16%	4
Sun 4p	Mostly sunny	64°18° (likely 64°18° to 66°19°)	64°18°	0%	1 mph2 km/h from S, gusts 6 mph10 km/h	48%	14%	3
Sun 5p	Sunny	64°18° (likely 63°17° to 65°18°)	64°18°	0%	2 mph3 km/h from S, gusts 5 mph8 km/h	50%	15%	1
Sun 6p	Clear	61°16° (likely 59°15° to 61°16°)	61°16°	0%	1 mph2 km/h from S, gusts 6 mph9 km/h	56%	4%	0
Sun 7p	Clear	58°14° (likely 55°13° to 58°14°)	58°14°	0%	1 mph2 km/h from S, gusts 4 mph7 km/h	62%	0%	0
Sun 8p	Clear	54°12° (likely 52°11° to 54°12°)	54°12°	0%	1 mph2 km/h from S, gusts 4 mph6 km/h	74%	0%	0
Sun 9p	Clear	49°9° (likely 49°9° to 53°12°)	49°9°	0%	1 mph2 km/h from S, gusts 5 mph7 km/h	86%	0%	0
Sun 10p	Clear	47°8° (likely 47°8° to 53°12°)	47°8°	0%	1 mph2 km/h from S, gusts 4 mph6 km/h	93%	0%	0
Sun 11p	Clear	45°7° (likely 45°7° to 50°10°)	45°7°	0%	1 mph2 km/h from S, gusts 2 mph3 km/h	100%	0%	0
Mon 12a	Clear	44°7° (likely 44°7° to 48°9°)	44°7°	0%	1 mph2 km/h from S, gusts 3 mph4 km/h	96%	0%	0
Mon 1a	Clear	44°7° (likely 44°7° to 47°8°)	44°7°	0%	1 mph2 km/h from S, gusts 3 mph5 km/h	96%	1%	0
Mon 2a	Clear	42°6° (likely 42°6° to 46°8°)	42°6°	0%	1 mph2 km/h from W, gusts 3 mph5 km/h	96%	0%	0
Mon 3a	Clear	41°5° (likely 41°5° to 45°7°)	41°5°	0%	1 mph2 km/h from S, gusts 4 mph6 km/h	100%	6%	0
Mon 4a	Clear	40°4° (likely 40°4° to 44°7°)	40°4°	0%	1 mph2 km/h from S, gusts 4 mph6 km/h	100%	13%	0
Mon 5a	Clear	39°4° (likely 39°4° to 44°7°)	39°4°	0%	1 mph2 km/h from W, gusts 4 mph7 km/h	100%	17%	0
Mon 6a	Clear	38°3° (likely 38°3° to 43°6°)	38°3°	0%	1 mph2 km/h from SW, gusts 3 mph6 km/h	100%	23%	0
Mon 7a	Clear	38°3° (likely 38°3° to 42°6°)	38°3°	0%	1 mph2 km/h from W, gusts 4 mph6 km/h	100%	23%	0
Mon 8a	Sunny	38°3° (likely 38°3° to 42°6°)	38°3°	0%	1 mph2 km/h from W, gusts 4 mph7 km/h	96%	22%	0
Mon 9a	Sunny	43°6° (likely 42°6° to 46°8°)	43°6°	0%	1 mph2 km/h from NW, gusts 4 mph6 km/h	93%	22%	1
Mon 10a	Sunny	50°10° (likely 49°9° to 53°12°)	50°10°	0%	2 mph3 km/h from W, gusts 7 mph12 km/h	77%	6%	2
Mon 11a	Sunny	56°13° (likely 56°13° to 59°15°)	56°13°	0%	3 mph5 km/h from NW, gusts 8 mph12 km/h	66%	1%	3
Mon 12p	Sunny	60°16° (likely 60°16° to 63°17°)	60°16°	0%	5 mph8 km/h from NW, gusts 9 mph14 km/h	58%	2%	4
Mon 1p	Sunny	64°18° (likely 64°18° to 66°19°)	64°18°	0%	5 mph8 km/h from NW, gusts 10 mph15 km/h	52%	0%	4
Mon 2p	Sunny	67°19° (likely 67°19° to 68°20°)	67°19°	0%	6 mph10 km/h from NW, gusts 10 mph16 km/h	47%	0%	4
Mon 3p	Sunny	69°21° (likely 67°19° to 69°21°)	69°21°	0%	6 mph10 km/h from NW, gusts 12 mph19 km/h	44%	0%	4
Mon 4p	Sunny	69°21° (likely 67°19° to 69°21°)	69°21°	0%	5 mph8 km/h from NW, gusts 11 mph18 km/h	47%	0%	3
Mon 5p	Sunny	69°21° (likely 66°19° to 69°21°)	69°21°	0%	3 mph5 km/h from NW, gusts 10 mph16 km/h	49%	0%	1
Mon 6p	Clear	66°19° (likely 60°16° to 66°19°)	66°19°	0%	2 mph3 km/h from NW, gusts 5 mph7 km/h	54%	0%	0

Days ahead

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

Today, Oct 24. Mostly sunny. High 63°17°, low 36°2°. Typical 65°18° / 42°6°. Dry. Forecasts agree.
1. Evening
  6 PM–midnight
  Clear, 51°11°
  Dry
2. Overnight
  midnight–6 AM
  Clear, 39°4°
  Dry
Official NWS forecast
Tonight: Mostly clear, with a low around 36. South wind around 3 mph.
Forecasts agreeIndependent forecasts are close; the range is narrow.
High, likely
62°17°–64°18°
Low, likely
35°2°–38°3°
Typical high / low
65°18° / 42°6°
Wind
6 mph9 km/h, gusts 13 mph21 km/h
UV peak
4
Tomorrow, Oct 25. Mostly sunny. High 65°18°, low 37°3°. Typical 64°18° / 42°6°. Dry. Forecasts agree.
1. Morning
  6 AM–noon
  Sunny, 38°3°
  Dry
2. Afternoon
  noon–6 PM
  Mostly sunny, 64°18°
  Dry
3. Evening
  6 PM–midnight
  Clear, 54°12°
  Dry
4. Overnight
  midnight–6 AM
  Clear, 39°4°
  Dry
Official NWS forecast
Day: Sunny, with a high near 65. South wind around 2 mph.
Night: Mostly clear, with a low around 37. Southwest 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
6 mph9 km/h
UV peak
4
Monday, Oct 26. Mostly sunny. High 70°21°, low 46°8°. Typical 64°18° / 41°5°. Dry. Forecasts agree.
1. Morning
  6 AM–noon
  Sunny, 38°3°
  Dry
2. Afternoon
  noon–6 PM
  Sunny, 69°21°
  Dry
3. Evening
  6 PM–midnight
  Clear, 55°13°
  Dry
4. Overnight
  midnight–6 AM
  Clear, 48°9°
  Dry
Official NWS forecast
Day: Sunny, with a high near 70. West wind 1 to 6 mph.
Night: Mostly clear, with a low around 46. Northwest wind around 3 mph.
Forecasts agreeIndependent forecasts are close; the range is narrow.
High, likely
67°19°–70°21°
Low, likely
38°3°–46°8°
Typical high / low
64°18° / 41°5°
Wind
6 mph10 km/h, gusts 15 mph24 km/h
UV peak
4
Tuesday, Oct 27. Mostly sunny. High 68°20°, low 45°7°. Typical 64°18° / 41°5°. Dry. Mostly agree.
1. Morning
  6 AM–noon
  Sunny, 47°8°
  Dry
2. Afternoon
  noon–6 PM
  Sunny, 66°19°
  Dry
3. Evening
  6 PM–midnight
  Mostly clear, 56°13°
  Dry
4. Overnight
  midnight–6 AM
  Mostly clear, 46°8°
  Dry
Hours this far out come from computer models only.
Official NWS forecast
Day: Sunny, with a high near 68.
Night: Mostly clear, with a low around 45.
Mostly agreeIndependent forecasts are fairly close; small surprises are possible.
High, likely
65°18°–69°21°
Low, likely
44°7°–49°9°
Typical high / low
64°18° / 41°5°
Wind
8 mph14 km/h, gusts 15 mph25 km/h
UV peak
4
Wednesday, Oct 28. Cloudy. High 66°19°, low 47°8°. Typical 64°18° / 41°5°. Dry. Mostly agree.
1. Morning
  6 AM–noon
  Cloudy, 47°8°
  Dry
2. Afternoon
  noon–6 PM
  Cloudy, 65°18°
  Dry
3. Evening
  6 PM–midnight
  Cloudy, 56°13°
  Dry
4. Overnight
  midnight–6 AM
  Cloudy, 49°9°
  Dry
Hours this far out come from computer models only.
Official NWS forecast
Day: Partly sunny, with a high near 66.
Night: Mostly cloudy, with a low around 47.
Mostly agreeIndependent forecasts are fairly close; small surprises are possible.
High, likely
63°17°–67°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. Cloudy. High 71°22°, low 48°9°. Typical 63°17° / 40°4°. Dry. Mostly agree.
1. Morning
  6 AM–noon
  Sunny, 47°8°
  Dry
2. Afternoon
  noon–6 PM
  Sunny, 69°21°
  Dry
3. Evening
  6 PM–midnight
  Clear, 58°15°
  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 71.
Night: Mostly clear, with a low around 48.
Mostly agreeIndependent forecasts are fairly close; small surprises are possible.
High, likely
68°20°–71°22°
Low, likely
46°8°–48°9°
Typical high / low
63°17° / 40°4°
Wind
7 mph11 km/h, gusts 24 mph38 km/h
UV peak
4
Friday, Oct 30. Mostly sunny. High 75°24°, 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, 75°24°
  Dry
3. Evening
  6 PM–midnight
  Clear, 62°16°
  Dry
4. Overnight
  midnight–6 AM
  Partly cloudy, 49°10°
  Dry
Hours this far out come from computer models only.
Official NWS forecast
Day: Sunny, with a high near 75.
Night: Mostly clear, with a low around 49.
Forecasts agreeIndependent forecasts are close; the range is narrow.
High, likely
74°23°–76°24°
Low, likely
43°6°–50°10°
Typical high / low
63°17° / 40°4°
Wind
6 mph10 km/h, gusts 26 mph42 km/h
UV peak
4
Saturday, Oct 31. Partly sunny. High 73°23°, low 49°9°. Typical 62°17° / 40°4°. Dry. Forecasts differ.
1. Morning
  6 AM–noon
  Partly sunny, 48°9°
  Dry
2. Afternoon
  noon–6 PM
  Cloudy, 72°22°
  Dry
3. Evening
  6 PM–midnight
  Cloudy, 59°15°
  Dry
4. Overnight
  midnight–6 AM
  Cloudy, 55°13°
  Dry
Hours this far out come from computer models only.
Official NWS forecast
Day: Mostly sunny, with a high near 73.
Forecasts differIndependent forecasts disagree; expect changes and plan for the range.
High, likely
65°18°–74°23°
Low, likely
44°7°–55°13°
Typical high / low
62°17° / 40°4°
Wind
7 mph11 km/h, gusts 28 mph44 km/h
UV peak
3
Sunday, Nov 1. Cloudy. High 71°22°, low 54°12°. Typical 62°17° / 40°4°. Rain 0.03 in0.8 mm, 30% chance. Mostly agree.
1. Morning
  6 AM–noon
  Cloudy, 55°13°
  Dry
2. Afternoon
  noon–6 PM
  Cloudy, 70°21°
  30% chance · 0.01 in0.3 mm
3. Evening
  6 PM–midnight
  Drizzle, 66°19°
  30% chance · 0.06 in1.4 mm
4. Overnight
  midnight–6 AM
  Showers, 62°17°
  30% chance · 0.13 in3.3 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.
Mostly agreeIndependent forecasts are fairly close; small surprises are possible.
High, likely
67°19°–73°23°
Low, likely
51°11°–57°14°
Typical high / low
62°17° / 40°4°
Wind
11 mph18 km/h, gusts 22 mph35 km/h
UV peak
4
Monday, Nov 2. Showers. High 74°23°, low 59°15°. Typical 62°17° / 39°4°. Rain 0.56 in14 mm, 30% chance. Mostly agree.
1. Morning
  6 AM–noon
  Drizzle, 63°17°
  30% chance · 0.08 in1.9 mm
2. Afternoon
  noon–6 PM
  Drizzle, 74°23°
  Dry
3. Evening
  6 PM–midnight
  Clear, 63°17°
  20% chance · 0.41 in10 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.
Mostly agreeIndependent forecasts are fairly close; small surprises are possible.
High, likely
72°22°–78°26°
Low, likely
56°13°–66°19°
Typical high / low
62°17° / 39°4°
Wind
18 mph28 km/h, gusts 39 mph62 km/h
UV peak
3

10 days15 days30 days

The outlook

Today
Dry, high 63°, low 36°.
Tomorrow
Dry, high 65°, low 37°.
Monday
Dry, high 70°, low 46°, warming up.
Rest of week
Mostly dry, highs 66–75°.

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

Potomac River at Edwards Ferry

5.7 mi

Below flood stage

Level: 3.8 ft

Forecast peak 3.9 ft Sat 8 PM

Reading from Sat 5:45 PM · NWS gauge page

Seneca Creek at Dawsonville

6.2 mi

Below flood stage

Level: 2.0 ft
Flow: 59 cfs

Forecast peak 2.0 ft Sat 8 PM

Reading from Sat 6:50 PM · NWS gauge page

Goose Creek near Leesburg

10 mi

Below flood stage

Level: 1.5 ft
Flow: 106 cfs

Forecast peak 1.6 ft Sun 2 AM

Reading from Sat 5:45 PM · NWS gauge page

Broad Run near Sterling

2.5 mi

Below flood stage

Level: 1.8 ft
Flow: 52 cfs

Reading from Sat 6:40 PM · 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: 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 14 hours are near freezing and damp, when outdoor units defrost more often.

Comfort

Dry air outside (dew point 41°F).

Open the windows?

Sun, 1:00 PM–6:00 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

Cascades weather by month: normals, records, snow and freeze dates

Sun & moon

Sun

Daylight: 10 h 50 min; Losing 2 min 21 s a day; shortest Dec 21, 1 h 25 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? Fair

Mostly clear 8 PM–7:02 AM, but the moon is 99% lit and up.

Moon

Waxing gibbous

98% lit · growing

Today: sets 5:41 AM · rises 5:14 PM
Full moon: Oct 26
New moon: Nov 9

Looking west from Cascades. The highest point on the skyline is about 3,400 ft, 52 mi away.Skyline from USGS elevation data, heights drawn up to 6× taller. Sky, sun and moon as they are now.

1 active weather alert

Frost Advisory

Cascades, VA weather

Next 2 hours

Next 48 hours

Days ahead

The outlook

Today

Tomorrow

Monday

Rest of week

What changed since yesterday

Radar

Rivers

Potomac River at Edwards Ferry

Seneca Creek at Dawsonville

Goose Creek near Leesburg

Broad Run near Sterling

For your home

Heating this week

Heat-pump hours, next 7 days

Comfort

Open the windows?

Is this typical?

Oct 24, today vs a typical year

Last 7 days vs normal

Sun & moon

Sun

Stars tonight? Fair

Moon