Frost Advisory
Starts in 9 h 58 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 2:15 PM EDT at KJYO

One Loudoun, VA weather

Sunny and 61°16°, jacket by 7 PM.

Mostly agree

Now 61°16°

Sunny

Wind: 8 mph13 km/h; From the south-southwest. Up to 8 mph13 km/h through 3 AM
Dew point: 43°6°; Comfortable
UV index: 4Moderate; Moderate until 5 PM
Air quality: 30Good; Ozone · tomorrow moderate
Pressure: 30.54 inHg1034 hPa; Falling · −0.06 inHg−2.1 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 4 PM
Below 50°10° tonight after 8 PM
Above 50°10° tomorrow by 11 AM
Drops 12°7° tomorrow night 6–9 PM (61°16° → 49°9°)
Fog Monday 8–9 AM

This afternoonNear 62°17° · Clear
TonightDown to 35°2° by 5 AM · Clear
Tomorrow morningUp to 53°12° by 11 AM · Clear
Tomorrow afternoonUp to 65°18° by 4 PM · Clear
Tomorrow nightDown to 38°3° by 4 AM · Clear
Monday morningUp to 57°14° by 11 AM · Clear
Monday afternoonUp to 68°20° by 2 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 3p	Sunny	62°17° (likely 61°16° to 63°17°)	62°17°	0%	5 mph8 km/h from SE, gusts 7 mph12 km/h	44%	12%	4
Sat 4p	Mostly sunny	63°17° (likely 61°16° to 64°18°)	63°17°	0%	5 mph8 km/h from SE, gusts 7 mph11 km/h	43%	20%	3
Sat 5p	Mostly sunny	61°16° (likely 60°16° to 64°18°)	61°16°	0%	5 mph8 km/h from SE, gusts 7 mph11 km/h	46%	25%	1
Sat 6p	Mostly clear	58°14° (likely 56°13° to 59°15°)	58°14°	0%	3 mph5 km/h from E, gusts 10 mph16 km/h	51%	25%	0
Sat 7p	Clear	54°12° (likely 53°12° to 55°13°)	54°12°	0%	3 mph5 km/h from E, gusts 8 mph13 km/h	61%	20%	0
Sat 8p	Clear	48°9° (likely 48°9° to 52°11°)	47°8°	0%	3 mph5 km/h from E, gusts 8 mph13 km/h	80%	18%	0
Sat 9p	Clear	43°6° (likely 43°6° to 50°10°)	43°6°	0%	2 mph3 km/h from E, gusts 7 mph12 km/h	96%	12%	0
Sat 10p	Clear	42°6° (likely 42°6° to 49°9°)	42°6°	0%	1 mph2 km/h from E, gusts 6 mph10 km/h	96%	9%	0
Sat 11p	Clear	41°5° (likely 41°5° to 47°8°)	41°5°	0%	1 mph2 km/h from E, gusts 5 mph9 km/h	100%	18%	0
Sun 12a	Mostly clear	39°4° (likely 39°4° to 47°8°)	39°4°	0%	1 mph2 km/h from NE, gusts 4 mph6 km/h	100%	27%	0
Sun 1a	Clear	39°4° (likely 39°4° to 46°8°)	39°4°	0%	0 mph0 km/h, gusts 4 mph6 km/h	100%	20%	0
Sun 2a	Clear	38°3° (likely 38°3° to 46°8°)	38°3°	0%	0 mph0 km/h, gusts 3 mph5 km/h	100%	22%	0
Sun 3a	Clear	36°2° (likely 36°2° to 45°7°)	36°2°	0%	0 mph0 km/h, gusts 3 mph5 km/h	100%	16%	0
Sun 4a	Clear	36°2° (likely 36°2° to 44°7°)	36°2°	0%	0 mph0 km/h, gusts 3 mph4 km/h	100%	14%	0
Sun 5a	Clear	35°2° (likely 35°2° to 43°6°)	35°2°	0%	0 mph0 km/h, gusts 3 mph5 km/h	100%	13%	0
Sun 6a	Clear	34°1° (likely 34°1° to 42°6°)	34°1°	0%	0 mph0 km/h, gusts 3 mph5 km/h	100%	13%	0
Sun 7a	Sunny	34°1° (likely 34°1° to 41°5°)	34°1°	0%	0 mph0 km/h, gusts 4 mph6 km/h	100%	9%	0
Sun 8a	Sunny	35°2° (likely 35°2° to 41°5°)	35°2°	0%	0 mph0 km/h, gusts 4 mph6 km/h	100%	5%	0
Sun 9a	Sunny	40°4° (likely 40°4° to 46°8°)	40°4°	0%	0 mph0 km/h, gusts 4 mph6 km/h	100%	8%	1
Sun 10a	Sunny	48°9° (likely 48°9° to 52°11°)	48°9°	0%	0 mph0 km/h, gusts 6 mph9 km/h	83%	5%	2
Sun 11a	Sunny	53°12° (likely 53°12° to 57°14°)	53°12°	0%	0 mph0 km/h, gusts 5 mph7 km/h	74%	4%	3
Sun 12p	Sunny	57°14° (likely 57°14° to 60°16°)	57°14°	0%	1 mph2 km/h from E, gusts 5 mph8 km/h	64%	7%	4
Sun 1p	Sunny	61°16° (likely 61°16° to 63°17°)	61°16°	0%	1 mph2 km/h from S, gusts 5 mph9 km/h	56%	7%	4
Sun 2p	Sunny	63°17° (likely 63°17° to 64°18°)	63°17°	0%	1 mph2 km/h from S, gusts 5 mph8 km/h	52%	8%	4
Sun 3p	Sunny	64°18° (likely 64°18° to 65°18°)	64°18°	0%	1 mph2 km/h from S, gusts 5 mph9 km/h	50%	7%	4
Sun 4p	Sunny	65°18° (likely 64°18° to 65°18°)	65°18°	0%	1 mph2 km/h from S, gusts 6 mph9 km/h	48%	11%	3
Sun 5p	Sunny	64°18° (likely 63°17° to 64°18°)	64°18°	0%	1 mph2 km/h from S, gusts 6 mph9 km/h	50%	17%	1
Sun 6p	Clear	61°16° (likely 59°15° to 61°16°)	61°16°	0%	0 mph0 km/h, gusts 5 mph8 km/h	56%	3%	0
Sun 7p	Clear	56°13° (likely 55°13° to 57°14°)	56°13°	0%	0 mph0 km/h, gusts 4 mph7 km/h	66%	1%	0
Sun 8p	Clear	49°9° (likely 49°9° to 55°13°)	49°9°	0%	0 mph0 km/h, gusts 3 mph6 km/h	86%	0%	0
Sun 9p	Clear	46°8° (likely 46°8° to 54°12°)	46°8°	0%	0 mph0 km/h, gusts 3 mph5 km/h	93%	0%	0
Sun 10p	Clear	45°7° (likely 45°7° to 53°12°)	45°7°	0%	0 mph0 km/h, gusts 3 mph4 km/h	96%	0%	0
Sun 11p	Clear	44°7° (likely 44°7° to 49°9°)	44°7°	0%	0 mph0 km/h, gusts 3 mph4 km/h	96%	0%	0
Mon 12a	Clear	42°6° (likely 42°6° to 48°9°)	42°6°	0%	0 mph0 km/h, gusts 3 mph4 km/h	100%	0%	0
Mon 1a	Clear	41°5° (likely 41°5° to 47°8°)	41°5°	0%	0 mph0 km/h, gusts 3 mph4 km/h	100%	0%	0
Mon 2a	Clear	40°4° (likely 40°4° to 46°8°)	40°4°	0%	1 mph2 km/h from W, gusts 3 mph5 km/h	100%	2%	0
Mon 3a	Clear	39°4° (likely 39°4° to 45°7°)	39°4°	0%	1 mph2 km/h from W, gusts 3 mph5 km/h	100%	12%	0
Mon 4a	Clear	38°3° (likely 38°3° to 44°7°)	38°3°	0%	1 mph2 km/h from W, gusts 3 mph5 km/h	100%	16%	0
Mon 5a	Clear	38°3° (likely 38°3° to 43°6°)	38°3°	0%	1 mph2 km/h from W, gusts 3 mph4 km/h	100%	18%	0
Mon 6a	Clear	38°3° (likely 38°3° to 42°6°)	38°3°	0%	1 mph2 km/h from W, gusts 3 mph5 km/h	96%	26%	0
Mon 7a	Partly cloudy	36°2° (likely 36°2° to 41°5°)	36°2°	0%	1 mph2 km/h from NW, gusts 3 mph5 km/h	100%	41%	0
Mon 8a	Fog	38°3° (likely 36°2° to 42°6°)	38°3°	0%	1 mph2 km/h from NW, gusts 3 mph4 km/h	96%	47%	0
Mon 9a	Sunny	42°6° (likely 37°3° to 50°10°)	42°6°	0%	1 mph2 km/h from NW, gusts 4 mph7 km/h	96%	29%	1
Mon 10a	Sunny	49°9° (likely 45°7° to 55°13°)	49°9°	0%	2 mph3 km/h from NW, gusts 5 mph8 km/h	80%	2%	2
Mon 11a	Sunny	57°14° (likely 53°12° to 60°16°)	57°14°	0%	3 mph5 km/h from NW, gusts 7 mph11 km/h	64%	0%	3
Mon 12p	Sunny	62°17° (likely 59°15° to 63°17°)	62°17°	0%	5 mph8 km/h from NW, gusts 8 mph13 km/h	56%	0%	4
Mon 1p	Sunny	66°19° (likely 63°17° to 67°19°)	66°19°	0%	5 mph8 km/h from NW, gusts 10 mph16 km/h	50%	0%	4
Mon 2p	Sunny	68°20° (likely 65°18° to 68°20°)	68°20°	0%	5 mph8 km/h from NW, gusts 11 mph17 km/h	47%	0%	4

Days ahead

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

Today, Oct 24. Mostly sunny. High 63°17°, low 34°1°. Typical 65°18° / 42°6°. Dry. Mostly agree.
1. Afternoon
  noon–6 PM
  Mostly sunny, 63°17°
  Dry
2. Evening
  6 PM–midnight
  Clear, 48°9°
  Dry
3. Overnight
  midnight–6 AM
  Clear, 35°2°
  Dry
Official NWS forecast
Today: Sunny, with a high near 63. Southeast wind around 5 mph.
Tonight: Patchy fog between 2am and 3am, then areas of frost and patchy fog. Mostly clear, with a low around 34. East wind 0 to 3 mph.
Mostly agreeIndependent forecasts are fairly close; small surprises are possible.
High, likely
60°16°–64°18°
Low, likely
34°1°–39°4°
Typical high / low
65°18° / 42°6°
Wind
7 mph10 km/h, gusts 14 mph23 km/h
UV peak
4
Tomorrow, Oct 25. Mostly sunny. High 65°18°, low 36°2°. Typical 64°18° / 42°6°. Dry. Forecasts agree.
1. Morning
  6 AM–noon
  Sunny, 35°2°
  Dry
2. Afternoon
  noon–6 PM
  Sunny, 65°18°
  Dry
3. Evening
  6 PM–midnight
  Clear, 49°9°
  Dry
4. Overnight
  midnight–6 AM
  Clear, 38°3°
  Dry
Official NWS forecast
Day: Areas of frost and patchy fog before 9am. Sunny, with a high near 65. South wind around 1 mph.
Night: Mostly clear, with a low around 36. West wind around 1 mph.
Forecasts agreeIndependent forecasts are close; the range is narrow.
High, likely
64°18°–65°18°
Low, likely
36°2°–41°5°
Typical high / low
64°18° / 42°6°
Wind
5 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, 68°20°
  Dry
3. Evening
  6 PM–midnight
  Clear, 55°13°
  Dry
4. Overnight
  midnight–6 AM
  Clear, 47°8°
  Dry
Official NWS forecast
Day: Patchy frost between 7am and 8am. Sunny, with a high near 70. Northwest wind 1 to 5 mph.
Night: Mostly clear, with a low around 46.
Forecasts agreeIndependent forecasts are close; the range is narrow.
High, likely
67°19°–70°21°
Low, likely
36°2°–46°8°
Typical high / low
64°18° / 41°5°
Wind
7 mph12 km/h, gusts 14 mph23 km/h
UV peak
4
Tuesday, Oct 27. Mostly sunny. High 69°21°, 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
  Clear, 56°13°
  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 69.
Night: Mostly clear, with a low around 45.
Mostly agreeIndependent forecasts are fairly close; small surprises are possible.
High, likely
64°18°–69°21°
Low, likely
43°6°–49°9°
Typical high / low
64°18° / 41°5°
Wind
9 mph15 km/h, gusts 15 mph24 km/h
UV peak
4
Wednesday, Oct 28. Mostly cloudy. High 66°19°, low 46°8°. Typical 64°18° / 41°5°. Dry. Mostly agree.
1. Morning
  6 AM–noon
  Cloudy, 45°7°
  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, 48°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 46.
Mostly agreeIndependent forecasts are fairly close; small surprises are possible.
High, likely
63°17°–66°19°
Low, likely
42°6°–47°8°
Typical high / low
64°18° / 41°5°
Wind
7 mph11 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
  Partly sunny, 47°8°
  Dry
2. Afternoon
  noon–6 PM
  Partly sunny, 69°20°
  Dry
3. Evening
  6 PM–midnight
  Clear, 58°14°
  Dry
4. Overnight
  midnight–6 AM
  Clear, 47°8°
  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
67°19°–71°22°
Low, likely
45°7°–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 74°23°, low 49°9°. Typical 63°17° / 40°4°. Dry. Forecasts agree.
1. Morning
  6 AM–noon
  Sunny, 46°8°
  Dry
2. Afternoon
  noon–6 PM
  Sunny, 75°24°
  Dry
3. Evening
  6 PM–midnight
  Clear, 60°16°
  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 74.
Night: Mostly clear, with a low around 49.
Forecasts agreeIndependent forecasts are close; the range is narrow.
High, likely
74°23°–75°24°
Low, likely
42°6°–49°9°
Typical high / low
63°17° / 40°4°
Wind
8 mph13 km/h, gusts 26 mph42 km/h
UV peak
4
Saturday, Oct 31. Cloudy. High 72°22°, low 48°9°. Typical 62°17° / 40°4°. Dry. Mostly agree.
1. Morning
  6 AM–noon
  Mostly sunny, 47°9°
  Dry
2. Afternoon
  noon–6 PM
  Cloudy, 74°23°
  Dry
3. Evening
  6 PM–midnight
  Cloudy, 61°16°
  Dry
4. Overnight
  midnight–6 AM
  Cloudy, 56°13°
  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.
Mostly agreeIndependent forecasts are fairly close; small surprises are possible.
High, likely
69°21°–75°24°
Low, likely
44°7°–51°11°
Typical high / low
62°17° / 40°4°
Wind
7 mph11 km/h, gusts 28 mph44 km/h
UV peak
4
Sunday, Nov 1. Cloudy. High 70°21°, low 54°12°. Typical 62°17° / 40°4°. Rain 0.03 in0.8 mm, 30% chance. Forecasts differ.
1. Morning
  6 AM–noon
  Cloudy, 57°14°
  Dry
2. Afternoon
  noon–6 PM
  Cloudy, 69°21°
  30% chance
3. Evening
  6 PM–midnight
  Cloudy, 65°18°
  30% chance · 0.01 in0.3 mm
4. Overnight
  midnight–6 AM
  Drizzle, 63°17°
  30% chance · 0.06 in1.5 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
64°18°–74°23°
Low, likely
52°11°–57°14°
Typical high / low
62°17° / 40°4°
Wind
10 mph17 km/h, gusts 22 mph36 km/h
UV peak
2
Monday, Nov 2. Drizzle. High 72°22°, low 58°14°. Typical 62°17° / 39°4°. Rain 0.47 in12 mm, 30% chance. Forecasts differ.
1. Morning
  6 AM–noon
  Cloudy, 64°18°
  Dry
2. Afternoon
  noon–6 PM
  Drizzle, 72°22°
  Dry
3. Evening
  6 PM–midnight
  Drizzle, 65°18°
  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.
Forecasts differIndependent forecasts disagree; expect changes and plan for the range.
High, likely
63°17°–79°26°
Low, likely
50°10°–66°19°
Typical high / low
62°17° / 39°4°
Wind
18 mph28 km/h, gusts 39 mph62 km/h

10 days15 days30 days

The outlook

Today
Dry, high 63°, low 34°.
Tomorrow
Dry, high 65°, low 36°.
Monday
Dry, high 70°, low 46°, warming up.
Rest of week
Mostly dry, highs 66–74°.

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

3.4 mi

Below flood stage

Level: 3.9 ft

Forecast peak 3.9 ft Sat 8 PM

Reading from Sat 12:45 PM · NWS gauge page

Goose Creek near Leesburg

6.9 mi

Below flood stage

Level: 1.5 ft
Flow: 106 cfs

Forecast peak 1.6 ft Sun 2 AM

Reading from Sat 12:45 PM · NWS gauge page

Seneca Creek at Dawsonville

8.3 mi

Below flood stage

Level: 1.9 ft
Flow: 44 cfs

Forecast peak 2.0 ft Sat 8 PM

Reading from Sat 1:50 PM · NWS gauge page

Broad Run near Sterling

1.2 mi

Below flood stage

Level: 1.9 ft
Flow: 53 cfs

Reading from Sat 1:40 PM · NWS gauge page

For your home

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

Heating this week

About 61% less heating than a typical week.

This week 34Typical 88

Heating degree days, base 65°F

Heat-pump hours, next 7 days

h below 47°F: 26
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 22 hours are near freezing and damp, when outdoor units defrost more often.

Comfort

Dry air outside (dew point 43°F).

Open the windows?

Today, 4:00 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

One Loudoun weather by month: normals, records, snow and freeze dates

Sun & moon

Sun

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? Fair

Mostly clear 1–7:02 AM, but the moon is 99% lit and up.

Moon

Waxing gibbous

97% lit · growing

Today: sets 5:41 AM · rises 5:15 PM
Full moon: Oct 26
New moon: Nov 9

Looking west from One Loudoun. The highest point on the skyline is about 3,900 ft, 58 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

One Loudoun, 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

Goose Creek near Leesburg

Seneca Creek at Dawsonville

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