Frost Advisory
Starts in 4 h 45 min
When
From midnight tonight to 9 AM EDT Saturday.
Where
Portions of central, northern, and southern New Jersey and southeast Pennsylvania.
Issued for this forecast zone · National Weather Service Mount Holly NJ
What, impacts and precautionsHide details
What
Temperatures as low as 33 degrees 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: Middlesex; Western Monmouth; Mercer; Salem; Gloucester; Camden; Northwestern Burlington; Ocean; Cumberland; Atlantic; Southeastern Burlington; Delaware; Philadelphia; Eastern Chester; Eastern Montgomery; Lower Bucks
See it on weather.gov (opens in a new tab)

Observed 6:00 PM EDT at KPHL

Darby, PA weather

Mostly sunny and 59°15°.

Mostly agree

Now 59°15°

Mostly sunny

Wind: 6 mph9 km/h; From the east. Up to 6 mph9 km/h through 7 AM
Dew point: 34°1°; Dry, static shocks likely
UV tomorrow: 4Moderate; Moderate 11 AM–4 PM · peak 4
Air quality: 37Good; Main pollutant: PM2.5 (fine particles)
Pressure: 30.38 inHg1029 hPa; Rising slowly · +0.04 inHg+1.4 hPa in 3 h

No precipitation expected in the next 2 hours.

From forecast models

Next 48 hours

Good hours for

Below 50°10° tonight after 9 PM
Low 37°3° tomorrow at 6 AM
Above 50°10° tomorrow by 10 AM
High 64°18° tomorrow at 3 PM

TonightDown to 38°3° by 3 AM · Partly cloudy
Tomorrow morningUp to 56°13° by 11 AM · Partly cloudy
Tomorrow afternoonUp to 64°18° by 3 PM · Clear
Tomorrow nightDown to 38°3° by 4 AM · Clear
Sunday morningUp to 58°14° by 11 AM · Clear
Sunday afternoonUp to 67°19° 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
Fri 7p	Clear	55°13° (likely 53°12° to 55°13°)	55°13°	0%	5 mph8 km/h from E, gusts 7 mph12 km/h	45%	2%	0
Fri 8p	Mostly clear	50°10° (likely 50°10° to 52°11°)	50°10°	0%	5 mph8 km/h from E, gusts 7 mph11 km/h	58%	37%	0
Fri 9p	Partly cloudy	47°8° (likely 47°8° to 50°10°)	47°8°	0%	0 mph0 km/h, gusts 6 mph10 km/h	68%	47%	0
Fri 10p	Mostly clear	44°7° (likely 44°7° to 48°9°)	44°7°	0%	0 mph0 km/h, gusts 6 mph10 km/h	76%	30%	0
Fri 11p	Cloudy	43°6° (likely 43°6° to 47°8°)	43°6°	0%	0 mph0 km/h, gusts 4 mph6 km/h	79%	76%	0
Sat 12a	Partly cloudy	42°6° (likely 42°6° to 46°8°)	42°6°	0%	0 mph0 km/h, gusts 3 mph5 km/h	82%	65%	0
Sat 1a	Mostly clear	41°5° (likely 41°5° to 45°7°)	41°5°	0%	0 mph0 km/h, gusts 3 mph5 km/h	86%	36%	0
Sat 2a	Clear	40°4° (likely 40°4° to 45°7°)	40°4°	0%	0 mph0 km/h, gusts 3 mph5 km/h	85%	4%	0
Sat 3a	Clear	38°3° (likely 38°3° to 44°7°)	38°3°	0%	0 mph0 km/h, gusts 3 mph5 km/h	92%	4%	0
Sat 4a	Clear	38°3° (likely 38°3° to 44°7°)	38°3°	0%	0 mph0 km/h, gusts 4 mph7 km/h	92%	10%	0
Sat 5a	Clear	38°3° (likely 38°3° to 42°6°)	38°3°	0%	5 mph8 km/h from N, gusts 5 mph8 km/h	92%	15%	0
Sat 6a	Mostly clear	37°3° (likely 37°3° to 41°5°)	37°3°	0%	0 mph0 km/h, gusts 6 mph9 km/h	96%	39%	0
Sat 7a	Partly sunny	37°3° (likely 37°3° to 41°5°)	37°3°	0%	0 mph0 km/h, gusts 6 mph10 km/h	96%	53%	0
Sat 8a	Mostly sunny	39°4° (likely 39°4° to 42°6°)	37°3°	0%	5 mph8 km/h from N, gusts 7 mph11 km/h	89%	37%	0
Sat 9a	Mostly sunny	45°7° (likely 44°7° to 47°8°)	44°7°	0%	5 mph8 km/h from N, gusts 7 mph11 km/h	73%	53%	1
Sat 10a	Mostly sunny	52°11° (likely 50°10° to 53°12°)	52°11°	0%	5 mph8 km/h from N, gusts 6 mph10 km/h	59%	60%	2
Sat 11a	Sunny	56°13° (likely 54°12° to 57°14°)	56°13°	0%	5 mph8 km/h from NE, gusts 5 mph9 km/h	51%	41%	3
Sat 12p	Sunny	59°15° (likely 57°14° to 60°16°)	59°15°	0%	5 mph8 km/h from NE, gusts 5 mph9 km/h	45%	47%	4
Sat 1p	Sunny	62°17° (likely 59°15° to 62°17°)	62°17°	0%	5 mph8 km/h from E, gusts 4 mph7 km/h	39%	22%	4
Sat 2p	Sunny	63°17° (likely 60°16° to 63°17°)	63°17°	0%	5 mph8 km/h from E, gusts 4 mph7 km/h	35%	3%	4
Sat 3p	Sunny	64°18° (likely 60°16° to 64°18°)	64°18°	0%	0 mph0 km/h, gusts 4 mph7 km/h	34%	4%	3
Sat 4p	Sunny	64°18° (likely 60°16° to 64°18°)	64°18°	0%	0 mph0 km/h, gusts 3 mph5 km/h	35%	1%	2
Sat 5p	Sunny	64°18° (likely 60°16° to 64°18°)	64°18°	0%	0 mph0 km/h, gusts 3 mph6 km/h	35%	0%	1
Sat 6p	Clear	62°17° (likely 57°14° to 62°17°)	62°17°	0%	0 mph0 km/h, gusts 4 mph6 km/h	39%	0%	0
Sat 7p	Clear	58°14° (likely 54°12° to 58°14°)	58°14°	0%	0 mph0 km/h, gusts 3 mph5 km/h	47%	0%	0
Sat 8p	Clear	54°12° (likely 52°11° to 54°12°)	54°12°	0%	0 mph0 km/h, gusts 3 mph5 km/h	57%	0%	0
Sat 9p	Clear	48°9° (likely 48°9° to 52°11°)	48°9°	0%	0 mph0 km/h, gusts 2 mph3 km/h	74%	0%	0
Sat 10p	Clear	46°8° (likely 46°8° to 49°9°)	46°8°	0%	0 mph0 km/h, gusts 3 mph5 km/h	79%	0%	0
Sat 11p	Clear	45°7° (likely 45°7° to 48°9°)	45°7°	0%	0 mph0 km/h, gusts 5 mph8 km/h	82%	2%	0
Sun 12a	Clear	44°7° (likely 44°7° to 47°8°)	44°7°	0%	0 mph0 km/h, gusts 4 mph7 km/h	86%	1%	0
Sun 1a	Clear	42°6° (likely 42°6° to 46°8°)	42°6°	0%	0 mph0 km/h, gusts 4 mph6 km/h	96%	1%	0
Sun 2a	Clear	41°5° (likely 41°5° to 45°7°)	41°5°	0%	0 mph0 km/h, gusts 4 mph6 km/h	96%	1%	0
Sun 3a	Clear	40°4° (likely 40°4° to 45°7°)	40°4°	0%	0 mph0 km/h, gusts 4 mph6 km/h	100%	0%	0
Sun 4a	Clear	38°3° (likely 38°3° to 44°7°)	38°3°	0%	0 mph0 km/h, gusts 4 mph6 km/h	100%	0%	0
Sun 5a	Clear	38°3° (likely 38°3° to 43°6°)	38°3°	0%	0 mph0 km/h, gusts 4 mph7 km/h	100%	0%	0
Sun 6a	Clear	37°3° (likely 37°3° to 42°6°)	37°3°	0%	0 mph0 km/h, gusts 4 mph7 km/h	100%	0%	0
Sun 7a	Sunny	37°3° (likely 37°3° to 41°5°)	37°3°	0%	0 mph0 km/h, gusts 4 mph7 km/h	100%	0%	0
Sun 8a	Sunny	39°4° (likely 38°3° to 41°5°)	39°4°	0%	0 mph0 km/h, gusts 4 mph7 km/h	100%	0%	0
Sun 9a	Sunny	45°7° (likely 43°6° to 46°8°)	45°7°	0%	0 mph0 km/h, gusts 3 mph5 km/h	82%	0%	1
Sun 10a	Sunny	51°11° (likely 51°11° to 53°12°)	51°11°	0%	0 mph0 km/h, gusts 4 mph6 km/h	66%	1%	2
Sun 11a	Sunny	58°14° (likely 57°14° to 59°15°)	58°14°	0%	0 mph0 km/h, gusts 6 mph9 km/h	55%	2%	3
Sun 12p	Sunny	62°17° (likely 59°15° to 62°17°)	62°17°	0%	0 mph0 km/h, gusts 5 mph7 km/h	46%	2%	4
Sun 1p	Sunny	64°18° (likely 62°17° to 64°18°)	64°18°	0%	0 mph0 km/h, gusts 5 mph8 km/h	41%	1%	4
Sun 2p	Sunny	66°19° (likely 63°17° to 66°19°)	66°19°	0%	0 mph0 km/h, gusts 5 mph7 km/h	37%	1%	4
Sun 3p	Sunny	67°19° (likely 64°18° to 67°19°)	67°19°	0%	0 mph0 km/h, gusts 5 mph7 km/h	36%	0%	3
Sun 4p	Sunny	67°19° (likely 64°18° to 67°19°)	67°19°	0%	0 mph0 km/h, gusts 5 mph7 km/h	36%	0%	2
Sun 5p	Sunny	66°19° (likely 63°17° to 66°19°)	66°19°	0%	0 mph0 km/h, gusts 4 mph6 km/h	38%	0%	1
Sun 6p	Clear	62°17° (likely 60°16° to 62°17°)	62°17°	0%	0 mph0 km/h, gusts 4 mph6 km/h	46%	0%	0

Days ahead

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

Today, Oct 23. Cloudy. High 62°17°, low 37°3°. Typical 64°18° / 46°8°. Dry. Mostly agree.
1. Evening
  6 PM–midnight
  Partly cloudy, 50°10°
  Dry
2. Overnight
  midnight–6 AM
  Clear, 38°3°
  Dry
Official NWS forecast
Tonight: Patchy frost after midnight. Partly cloudy, with a low around 37. East wind 0 to 5 mph.
Mostly agreeIndependent forecasts are fairly close; small surprises are possible.
High, likely
61°16°–63°17°
Low, likely
37°3°–47°8°
Typical high / low
64°18° / 46°8°
Wind
13 mph20 km/h, gusts 25 mph40 km/h
UV peak
4
Tomorrow, Oct 24. Mostly sunny. High 64°18°, low 37°3°. Typical 64°18° / 46°8°. Dry. Mostly agree.
1. Morning
  6 AM–noon
  Mostly sunny, 39°4°
  Dry
2. Afternoon
  noon–6 PM
  Sunny, 64°18°
  Dry
3. Evening
  6 PM–midnight
  Clear, 54°12°
  Dry
4. Overnight
  midnight–6 AM
  Clear, 38°3°
  Dry
Official NWS forecast
Day: Patchy frost before 10am. Sunny, with a high near 64. Northeast wind 0 to 5 mph.
Night: Patchy frost after 10pm. Mostly clear, with a low around 37. West wind around 0 mph.
Mostly agreeIndependent forecasts are fairly close; small surprises are possible.
High, likely
60°16°–64°18°
Low, likely
37°3°–41°5°
Typical high / low
64°18° / 46°8°
Wind
5 mph9 km/h
UV peak
4
Sunday, Oct 25. Sunny. High 67°19°, low 42°6°. Typical 64°18° / 46°8°. Dry. Forecasts agree.
1. Morning
  6 AM–noon
  Sunny, 39°4°
  Dry
2. Afternoon
  noon–6 PM
  Sunny, 67°19°
  Dry
3. Evening
  6 PM–midnight
  Clear, 55°13°
  Dry
4. Overnight
  midnight–6 AM
  Clear, 44°7°
  Dry
Official NWS forecast
Day: Patchy frost before 9am. Sunny, with a high near 67. Northwest wind around 0 mph.
Night: Clear, with a low around 42. West wind around 0 mph.
Forecasts agreeIndependent forecasts are close; the range is narrow.
High, likely
64°18°–67°19°
Low, likely
38°3°–42°6°
Typical high / low
64°18° / 46°8°
Wind
5 mph9 km/h
UV peak
4
Monday, Oct 26. Mostly sunny. High 69°21°, low 50°10°. Typical 63°17° / 45°7°. Dry. Forecasts agree.
1. Morning
  6 AM–noon
  Sunny, 44°7°
  Dry
2. Afternoon
  noon–6 PM
  Sunny, 69°20°
  Dry
3. Evening
  6 PM–midnight
  Clear, 58°15°
  Dry
4. Overnight
  midnight–6 AM
  Clear, 53°12°
  Dry
Hours this far out come from computer models only.
Official NWS forecast
Day: Sunny, with a high near 69.
Night: Clear, with a low around 50.
Forecasts agreeIndependent forecasts are close; the range is narrow.
High, likely
68°20°–69°21°
Low, likely
39°4°–50°10°
Typical high / low
63°17° / 45°7°
Wind
7 mph12 km/h, gusts 16 mph26 km/h
UV peak
4
Tuesday, Oct 27. Mostly sunny. High 67°19°, low 46°8°. Typical 63°17° / 45°7°. Dry. Forecasts differ.
1. Morning
  6 AM–noon
  Sunny, 51°11°
  Dry
2. Afternoon
  noon–6 PM
  Sunny, 65°18°
  Dry
3. Evening
  6 PM–midnight
  Clear, 55°13°
  Dry
4. Overnight
  midnight–6 AM
  Clear, 45°7°
  Dry
Hours this far out come from computer models only.
Official NWS forecast
Day: Sunny, with a high near 67.
Night: Partly cloudy, with a low around 46.
Forecasts differIndependent forecasts disagree; expect changes and plan for the range.
High, likely
62°17°–67°19°
Low, likely
46°8°–52°11°
Typical high / low
63°17° / 45°7°
Wind
9 mph15 km/h, gusts 22 mph36 km/h
UV peak
4
Wednesday, Oct 28. Cloudy. High 64°18°, low 49°9°. Typical 63°17° / 45°7°. Dry. Mostly agree.
1. Morning
  6 AM–noon
  Partly sunny, 45°7°
  Dry
2. Afternoon
  noon–6 PM
  Cloudy, 63°17°
  Dry
3. Evening
  6 PM–midnight
  Cloudy, 56°13°
  Dry
4. Overnight
  midnight–6 AM
  Cloudy, 49°10°
  Dry
Hours this far out come from computer models only.
Official NWS forecast
Day: Mostly sunny, with a high near 64.
Night: Mostly cloudy, with a low around 49.
Mostly agreeIndependent forecasts are fairly close; small surprises are possible.
High, likely
61°16°–65°18°
Low, likely
41°5°–49°9°
Typical high / low
63°17° / 45°7°
Wind
7 mph11 km/h, gusts 14 mph22 km/h
UV peak
4
Thursday, Oct 29. Cloudy. High 69°21°, low 52°11°. Typical 62°17° / 44°7°. Dry. Mostly agree.
1. Morning
  6 AM–noon
  Sunny, 49°10°
  Dry
2. Afternoon
  noon–6 PM
  Sunny, 68°20°
  Dry
3. Evening
  6 PM–midnight
  Clear, 59°15°
  Dry
4. Overnight
  midnight–6 AM
  Clear, 52°11°
  Dry
Hours this far out come from computer models only.
Official NWS forecast
Day: Mostly sunny, with a high near 69.
Night: Partly cloudy, with a low around 52.
Mostly agreeIndependent forecasts are fairly close; small surprises are possible.
High, likely
66°19°–69°21°
Low, likely
46°8°–52°11°
Typical high / low
62°17° / 44°7°
Wind
9 mph14 km/h, gusts 29 mph47 km/h
UV peak
4
Friday, Oct 30. Partly sunny. High 70°21°, low 50°10°. Typical 62°17° / 44°7°. Dry. Forecasts differ.
1. Morning
  6 AM–noon
  Sunny, 51°10°
  Dry
2. Afternoon
  noon–6 PM
  Sunny, 69°20°
  Dry
3. Evening
  6 PM–midnight
  Clear, 59°15°
  Dry
4. Overnight
  midnight–6 AM
  Clear, 50°10°
  Dry
Hours this far out come from computer models only.
Official NWS forecast
Day: Mostly sunny, with a high near 70.
Forecasts differIndependent forecasts disagree; expect changes and plan for the range.
High, likely
65°18°–73°23°
Low, likely
50°10°–51°11°
Typical high / low
62°17° / 44°7°
Wind
8 mph12 km/h, gusts 17 mph27 km/h
UV peak
4
Saturday, Oct 31. Cloudy. High 69°21°, low 48°9°. Typical 62°17° / 44°7°. Dry. Mostly agree.
1. Morning
  6 AM–noon
  Sunny, 48°9°
  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, 50°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.
Mostly agreeIndependent forecasts are fairly close; small surprises are possible.
High, likely
67°19°–70°21°
Low, likely
42°6°–56°13°
Typical high / low
62°17° / 44°7°
Wind
8 mph13 km/h
UV peak
4
Sunday, Nov 1. Cloudy. High 67°19°, low 50°10°. Typical 61°16° / 43°6°. Rain 0.01 in0.3 mm, 20% chance. Forecasts differ.
1. Morning
  6 AM–noon
  Cloudy, 50°10°
  Dry
2. Afternoon
  noon–6 PM
  Cloudy, 66°19°
  20% chance
3. Evening
  6 PM–midnight
  Cloudy, 62°16°
  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
63°17°–71°22°
Low, likely
45°7°–56°13°
Typical high / low
61°16° / 43°6°
Wind
9 mph15 km/h, gusts 27 mph44 km/h
UV peak
2

10 days15 days30 days

The outlook

Today
Dry, high 62°, low 37°.
Tomorrow
Dry, high 64°, low 37°.
Sunday
Dry, high 67°, low 42°, warming up.
Rest of week
Mostly dry, highs 64–70°.

Want the meteorologists’ reasoning? Read the NWS forecast discussion (PHI) (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

Schuylkill River near Philadelphia near 30th Street

4.9 mi

Below flood stage

Level: -1.2 ft

Forecast peak 4.8 ft Sat 12 AM

Reading from Fri 6 PM · NWS gauge page

Schuylkill River at Philadelphia

5.0 mi

Below flood stage

Level: 6.1 ft
Flow: 1,060 cfs

Forecast peak 6.1 ft Fri 8 PM

Reading from Fri 5 PM · NWS gauge page

Delaware River at USCG Station Washington Street (IN MLLW)

6.4 mi

Below flood stage

Level: 2.0 ft

Forecast peak 8.0 ft Sat 12 AM

Reading from Fri 6:06 PM · NWS gauge page

Cobbs Creek at Mt. Moriah Cemetery

1.5 mi

Below flood stage

Level: 2.1 ft
Flow: 32 cfs

Reading from Fri 6:30 PM · NWS gauge page

For your home

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

Heating this week

About 60% less heating than a typical week.

This week 30Typical 75

Heating degree days, base 65°F

Heat-pump hours, next 7 days

h below 47°F: 25
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 17 hours are near freezing and damp, when outdoor units defrost more often.

Comfort

Dry air outside (dew point 34°F).

Open the windows?

Sat, 1:00 PM–6:00 PM

Good stretch to open the windows.

Is this typical?

Philadelphia International Airport · official normals 1991–2020 · records 1873–2026

Oct 23, today vs a typical year

Today’s expected high is 2°1° colder than typical.

Last 7 days vs normal

On average 1° colder than normal (daily mean temperature).

−4°−2°SatOct 17
−6°−3°SunOct 18
−2°−1°MonOct 19
+3°+1°TueOct 20
+2°+1°WedOct 21
+2°+1°ThuOct 22
—FriOct 23

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

Sun & moon

Sun

Daylight: 10 h 50 min; Losing 2 min 30 s a day; shortest Dec 21, 1 h 30 min less
Golden hour: 5:32–6:26 PM; Morning 7:03–7:57 AM
Blue hour: 6:26–6:37 PM; Morning 6:52–7:03 AM; first light 6:52 AM

Stars tonight? Fair

Mostly clear 2–6 AM, but the moon is 95% lit and up.

Moon

Waxing gibbous

94% lit · growing

Today: sets 4:24 AM · rises 4:40 PM
Full moon: Oct 26
New moon: Nov 9

Looking west from Darby. The highest point on the skyline is about 4,200 ft, 54 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

Darby, PA weather

Next 2 hours

Next 48 hours

Days ahead

The outlook

Today

Tomorrow

Sunday

Rest of week

What changed since yesterday

Radar

Rivers

Schuylkill River near Philadelphia near 30th Street

Schuylkill River at Philadelphia

Delaware River at USCG Station Washington Street (IN MLLW)

Cobbs Creek at Mt. Moriah Cemetery

For your home

Heating this week

Heat-pump hours, next 7 days

Comfort

Open the windows?

Is this typical?

Oct 23, today vs a typical year

Last 7 days vs normal

Sun & moon

Sun

Stars tonight? Fair

Moon