Frost Advisory
Starts in 4 h 45 min
When
From 10 PM this evening to 9 AM EDT Sunday.
Where
In Delaware, Kent and New Castle Counties. In Maryland, Caroline, Kent MD, and Queen Annes Counties. In Pennsylvania, Delaware, Eastern Chester, Eastern Montgomery, Lower Bucks, and Philadelphia Counties.
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: New Castle; Kent; Kent; Queen Anne's; Caroline; Delaware; Philadelphia; Eastern Chester; Eastern Montgomery; Lower Bucks
See it on weather.gov (opens in a new tab)

Observed 4:55 PM EDT at KPTW

Norristown, PA weather

Sunny and 61°16°, jacket by 7 PM.

Forecasts agree

Now 61°16°

Sunny

Wind: 3 mph5 km/h; From the east. Light through 5 AM
Dew point: 34°1°; Dry, static shocks likely
UV tomorrow: 4Moderate; Moderate 11 AM–4 PM · peak 4
Air quality: 55Moderate; Main pollutant: PM2.5 (fine particles)
Pressure: 30.53 inHg1034 hPa; Falling slowly · −0.03 inHg−0.9 hPa in 3 h

No precipitation expected in the next 2 hours.

From forecast models

Next 48 hours

About the same as this time yesterday (61°16° then, 61°16° now)

Good hours for

Below 50°10° tonight after 8 PM
Low 34°1° tomorrow at 6 AM
Above 50°10° tomorrow by 10 AM
High 66°19° tomorrow at 3 PM

TonightDown to 35°2° by 4 AM · Clear
Tomorrow morningUp to 57°14° by 11 AM · Clear
Tomorrow afternoonUp to 66°19° by 3 PM · Clear
Tomorrow nightDown to 40°4° by 3 AM · Clear
Monday morningUp to 59°15° 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 5p	Sunny	63°17° (likely 59°15° to 63°17°)	63°17°	0%	0 mph0 km/h, gusts 2 mph4 km/h	34%	0%	0
Sat 6p	Clear	59°15° (likely 56°13° to 59°15°)	59°15°	0%	0 mph0 km/h, gusts 3 mph5 km/h	39%	0%	0
Sat 7p	Clear	55°13° (likely 52°11° to 55°13°)	55°13°	0%	0 mph0 km/h, gusts 3 mph5 km/h	45%	0%	0
Sat 8p	Clear	48°9° (likely 48°9° to 53°12°)	48°9°	0%	0 mph0 km/h, gusts 2 mph4 km/h	60%	0%	0
Sat 9p	Clear	45°7° (likely 45°7° to 51°11°)	45°7°	0%	0 mph0 km/h, gusts 3 mph5 km/h	68%	0%	0
Sat 10p	Clear	43°6° (likely 43°6° to 50°10°)	43°6°	0%	0 mph0 km/h, gusts 3 mph5 km/h	76%	0%	0
Sat 11p	Clear	40°4° (likely 40°4° to 48°9°)	40°4°	0%	0 mph0 km/h, gusts 3 mph4 km/h	85%	0%	0
Sun 12a	Clear	39°4° (likely 39°4° to 47°8°)	39°4°	0%	0 mph0 km/h, gusts 3 mph4 km/h	85%	0%	0
Sun 1a	Clear	37°3° (likely 37°3° to 46°8°)	37°3°	0%	0 mph0 km/h, gusts 3 mph5 km/h	92%	0%	0
Sun 2a	Clear	36°2° (likely 36°2° to 44°7°)	36°2°	0%	0 mph0 km/h, gusts 3 mph4 km/h	92%	0%	0
Sun 3a	Clear	36°2° (likely 36°2° to 43°6°)	36°2°	0%	0 mph0 km/h, gusts 3 mph4 km/h	92%	0%	0
Sun 4a	Clear	35°2° (likely 35°2° to 42°6°)	35°2°	0%	0 mph0 km/h, gusts 3 mph5 km/h	96%	0%	0
Sun 5a	Clear	35°2° (likely 35°2° to 40°4°)	35°2°	0%	0 mph0 km/h, gusts 2 mph4 km/h	92%	0%	0
Sun 6a	Clear	34°1° (likely 34°1° to 40°4°)	34°1°	0%	0 mph0 km/h, gusts 3 mph4 km/h	96%	0%	0
Sun 7a	Sunny	34°1° (likely 34°1° to 39°4°)	34°1°	0%	0 mph0 km/h, gusts 3 mph5 km/h	96%	0%	0
Sun 8a	Sunny	35°2° (likely 35°2° to 39°4°)	35°2°	0%	0 mph0 km/h, gusts 3 mph5 km/h	96%	0%	0
Sun 9a	Sunny	43°6° (likely 40°4° to 45°7°)	43°6°	0%	0 mph0 km/h, gusts 4 mph6 km/h	76%	0%	1
Sun 10a	Sunny	51°11° (likely 50°10° to 53°12°)	51°11°	0%	0 mph0 km/h, gusts 3 mph5 km/h	61%	0%	2
Sun 11a	Sunny	57°14° (likely 57°14° to 58°14°)	57°14°	0%	0 mph0 km/h, gusts 5 mph9 km/h	51%	0%	3
Sun 12p	Sunny	61°16° (likely 60°16° to 61°16°)	61°16°	0%	0 mph0 km/h, gusts 6 mph10 km/h	42%	0%	4
Sun 1p	Sunny	63°17° (likely 62°17° to 64°18°)	63°17°	0%	0 mph0 km/h, gusts 7 mph11 km/h	39%	0%	4
Sun 2p	Sunny	65°18° (likely 63°17° to 65°18°)	65°18°	0%	0 mph0 km/h, gusts 6 mph10 km/h	35%	0%	4
Sun 3p	Sunny	66°19° (likely 64°18° to 66°19°)	66°19°	0%	0 mph0 km/h, gusts 7 mph11 km/h	34%	1%	3
Sun 4p	Sunny	66°19° (likely 64°18° to 66°19°)	66°19°	0%	0 mph0 km/h, gusts 6 mph10 km/h	36%	1%	2
Sun 5p	Sunny	65°18° (likely 62°17° to 65°18°)	65°18°	0%	0 mph0 km/h, gusts 6 mph10 km/h	38%	1%	1
Sun 6p	Clear	61°16° (likely 58°14° to 61°16°)	61°16°	0%	0 mph0 km/h, gusts 5 mph8 km/h	46%	0%	0
Sun 7p	Clear	58°14° (likely 54°12° to 58°14°)	58°14°	0%	0 mph0 km/h, gusts 6 mph9 km/h	53%	0%	0
Sun 8p	Clear	51°11° (likely 51°11° to 55°13°)	51°11°	0%	0 mph0 km/h, gusts 6 mph9 km/h	68%	0%	0
Sun 9p	Clear	48°9° (likely 48°9° to 53°12°)	48°9°	0%	0 mph0 km/h, gusts 5 mph9 km/h	80%	0%	0
Sun 10p	Clear	46°8° (likely 46°8° to 51°11°)	46°8°	0%	0 mph0 km/h, gusts 5 mph8 km/h	86%	0%	0
Sun 11p	Clear	43°6° (likely 43°6° to 49°9°)	43°6°	0%	0 mph0 km/h, gusts 6 mph9 km/h	96%	0%	0
Mon 12a	Clear	42°6° (likely 42°6° to 47°8°)	42°6°	0%	0 mph0 km/h, gusts 5 mph8 km/h	96%	0%	0
Mon 1a	Clear	41°5° (likely 41°5° to 46°8°)	41°5°	0%	0 mph0 km/h, gusts 6 mph10 km/h	100%	0%	0
Mon 2a	Clear	41°5° (likely 40°4° to 45°7°)	41°5°	0%	0 mph0 km/h, gusts 6 mph10 km/h	100%	3%	0
Mon 3a	Clear	40°4° (likely 39°4° to 45°7°)	40°4°	0%	0 mph0 km/h, gusts 7 mph11 km/h	100%	0%	0
Mon 4a	Clear	40°4° (likely 38°3° to 44°7°)	40°4°	0%	0 mph0 km/h, gusts 6 mph9 km/h	100%	0%	0
Mon 5a	Clear	40°4° (likely 38°3° to 44°7°)	40°4°	0%	0 mph0 km/h, gusts 8 mph12 km/h	96%	0%	0
Mon 6a	Partly cloudy	39°4° (likely 37°3° to 44°7°)	39°4°	0%	0 mph0 km/h, gusts 6 mph9 km/h	100%	42%	0
Mon 7a	Sunny	39°4° (likely 36°2° to 43°6°)	39°4°	0%	0 mph0 km/h, gusts 5 mph8 km/h	96%	15%	0
Mon 8a	Sunny	40°4° (likely 36°2° to 44°7°)	40°4°	0%	0 mph0 km/h, gusts 7 mph10 km/h	100%	15%	0
Mon 9a	Sunny	47°8° (likely 42°6° to 49°9°)	47°8°	0%	0 mph0 km/h, gusts 6 mph10 km/h	79%	14%	1
Mon 10a	Sunny	54°12° (likely 50°10° to 55°13°)	54°12°	0%	0 mph0 km/h, gusts 12 mph19 km/h	66%	9%	2
Mon 11a	Sunny	59°15° (likely 57°14° to 60°16°)	59°15°	0%	5 mph8 km/h from W, gusts 12 mph20 km/h	60%	7%	3
Mon 12p	Sunny	63°17° (likely 61°16° to 64°18°)	63°17°	0%	5 mph8 km/h from W, gusts 12 mph19 km/h	52%	0%	4
Mon 1p	Sunny	66°19° (likely 64°18° to 66°19°)	66°19°	0%	5 mph8 km/h from W, gusts 12 mph19 km/h	47%	0%	4
Mon 2p	Sunny	68°20° (likely 66°19° to 68°20°)	68°20°	0%	5 mph8 km/h from W, gusts 12 mph20 km/h	44%	1%	4
Mon 3p	Sunny	69°21° (likely 66°19° to 69°21°)	69°21°	0%	5 mph8 km/h from W, gusts 14 mph22 km/h	42%	2%	3
Mon 4p	Sunny	69°21° (likely 67°19° to 69°21°)	69°21°	0%	5 mph8 km/h from W, gusts 14 mph23 km/h	44%	2%	2

Days ahead

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

Today, Oct 24. Sunny. High 64°18°, low 34°1°. Typical 65°18° / 48°9°. Dry. Forecasts agree.
1. Evening
  6 PM–midnight
  Clear, 48°9°
  Dry
2. Overnight
  midnight–6 AM
  Clear, 35°2°
  Dry
Official NWS forecast
Today: Sunny, with a high near 64. Southwest wind around 0 mph.
Tonight: Widespread frost after 10pm. Clear, with a low around 34. Southwest wind around 0 mph.
Forecasts agreeIndependent forecasts are close; the range is narrow.
High, likely
61°16°–64°18°
Low, likely
33°1°–36°2°
Typical high / low
65°18° / 48°9°
Wind
5 mph8 km/h
UV peak
4
Tomorrow, Oct 25. Sunny. High 67°19°, low 39°4°. Typical 64°18° / 48°9°. Dry. Forecasts agree.
1. Morning
  6 AM–noon
  Sunny, 35°2°
  Dry
2. Afternoon
  noon–6 PM
  Sunny, 66°19°
  Dry
3. Evening
  6 PM–midnight
  Clear, 51°11°
  Dry
4. Overnight
  midnight–6 AM
  Clear, 40°4°
  Dry
Official NWS forecast
Day: Widespread frost before 9am. Sunny, with a high near 67. West wind around 0 mph.
Night: Mostly clear, with a low around 39. West wind around 0 mph.
Forecasts agreeIndependent forecasts are close; the range is narrow.
High, likely
64°18°–67°19°
Low, likely
34°1°–39°4°
Typical high / low
64°18° / 48°9°
Wind
6 mph9 km/h
UV peak
4
Monday, Oct 26. Sunny. High 69°21°, low 45°7°. Typical 64°18° / 47°8°. Dry. Forecasts agree.
1. Morning
  6 AM–noon
  Sunny, 40°4°
  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, 50°10°
  Dry
Official NWS forecast
Day: Sunny, with a high near 69. West wind 0 to 5 mph.
Night: Clear, with a low around 45.
Forecasts agreeIndependent forecasts are close; the range is narrow.
High, likely
67°19°–69°21°
Low, likely
35°2°–45°7°
Typical high / low
64°18° / 47°8°
Wind
7 mph12 km/h, gusts 17 mph28 km/h
UV peak
4
Tuesday, Oct 27. Mostly sunny. High 65°18°, low 39°4°. Typical 64°18° / 47°8°. Dry. Mostly agree.
1. Morning
  6 AM–noon
  Sunny, 48°9°
  Dry
2. Afternoon
  noon–6 PM
  Sunny, 62°17°
  Dry
3. Evening
  6 PM–midnight
  Clear, 52°11°
  Dry
4. Overnight
  midnight–6 AM
  Clear, 44°7°
  Dry
Hours this far out come from computer models only.
Official NWS forecast
Day: Sunny, with a high near 65.
Night: Mostly clear, with a low around 39.
Mostly agreeIndependent forecasts are fairly close; small surprises are possible.
High, likely
61°16°–65°18°
Low, likely
39°4°–50°10°
Typical high / low
64°18° / 47°8°
Wind
8 mph13 km/h, gusts 23 mph37 km/h
UV peak
4
Wednesday, Oct 28. Cloudy. High 64°18°, low 45°7°. Typical 63°17° / 47°8°. Dry. Mostly agree.
1. Morning
  6 AM–noon
  Sunny, 42°5°
  Dry
2. Afternoon
  noon–6 PM
  Cloudy, 62°17°
  Dry
3. Evening
  6 PM–midnight
  Partly cloudy, 54°12°
  Dry
4. Overnight
  midnight–6 AM
  Partly cloudy, 47°8°
  Dry
Hours this far out come from computer models only.
Official NWS forecast
Day: Mostly sunny, with a high near 64.
Night: Partly cloudy, with a low around 45.
Mostly agreeIndependent forecasts are fairly close; small surprises are possible.
High, likely
61°16°–64°18°
Low, likely
38°3°–45°7°
Typical high / low
63°17° / 47°8°
Wind
8 mph12 km/h, gusts 14 mph22 km/h
UV peak
4
Thursday, Oct 29. Cloudy. High 70°21°, low 48°9°. Typical 63°17° / 46°8°. Dry. Mostly agree.
1. Morning
  6 AM–noon
  Mostly sunny, 46°8°
  Dry
2. Afternoon
  noon–6 PM
  Sunny, 67°19°
  Dry
3. Evening
  6 PM–midnight
  Clear, 57°14°
  Dry
4. Overnight
  midnight–6 AM
  Clear, 49°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 48.
Mostly agreeIndependent forecasts are fairly close; small surprises are possible.
High, likely
65°18°–70°21°
Low, likely
43°6°–48°9°
Typical high / low
63°17° / 46°8°
Wind
7 mph12 km/h, gusts 29 mph47 km/h
UV peak
4
Friday, Oct 30. Mostly sunny. High 73°23°, low 49°9°. Typical 63°17° / 46°8°. Dry. Mostly agree.
1. Morning
  6 AM–noon
  Sunny, 49°10°
  Dry
2. Afternoon
  noon–6 PM
  Sunny, 74°23°
  Dry
3. Evening
  6 PM–midnight
  Clear, 60°16°
  Dry
4. 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 73.
Night: Mostly clear, with a low around 49.
Mostly agreeIndependent forecasts are fairly close; small surprises are possible.
High, likely
72°22°–74°23°
Low, likely
44°7°–51°11°
Typical high / low
63°17° / 46°8°
Wind
6 mph9 km/h, gusts 23 mph37 km/h
UV peak
4
Saturday, Oct 31. Cloudy. High 71°22°, low 49°9°. Typical 62°17° / 46°8°. Dry. Forecasts differ.
1. Morning
  6 AM–noon
  Mostly sunny, 49°10°
  Dry
2. Afternoon
  noon–6 PM
  Cloudy, 72°22°
  Dry
3. Evening
  6 PM–midnight
  Cloudy, 61°16°
  Dry
4. Overnight
  midnight–6 AM
  Cloudy, 55°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.
Forecasts differIndependent forecasts disagree; expect changes and plan for the range.
High, likely
65°18°–74°23°
Low, likely
44°7°–53°12°
Typical high / low
62°17° / 46°8°
Wind
7 mph12 km/h, gusts 24 mph39 km/h
UV peak
3
Sunday, Nov 1. Cloudy. High 69°21°, low 54°12°. Typical 62°17° / 46°8°. Rain 0.02 in0.5 mm, 30% chance. Forecasts differ.
1. Morning
  6 AM–noon
  Cloudy, 56°13°
  Dry
2. Afternoon
  noon–6 PM
  Cloudy, 69°21°
  20% chance
3. Evening
  6 PM–midnight
  Drizzle, 64°18°
  30% chance · 0.02 in0.5 mm
4. Overnight
  midnight–6 AM
  Drizzle, 62°17°
  30% chance · 0.09 in2.3 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.
Forecasts differIndependent forecasts disagree; expect changes and plan for the range.
High, likely
65°18°–74°23°
Low, likely
52°11°–56°13°
Typical high / low
62°17° / 46°8°
Wind
10 mph16 km/h, gusts 21 mph34 km/h
UV peak
2
Monday, Nov 2. Drizzle. High 72°22°, low 60°16°. Typical 62°17° / 45°7°. Rain 0.24 in6.1 mm, 30% chance. Forecasts differ.
1. Morning
  6 AM–noon
  Showers, 64°18°
  30% chance · 0.1 in2.6 mm
2. Afternoon
  noon–6 PM
  Drizzle, 72°22°
  30% chance · 0.08 in2 mm
3. Evening
  6 PM–midnight
  Drizzle, 68°20°
  20% chance · 0.05 in1.2 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
65°18°–78°26°
Low, likely
55°13°–66°19°
Typical high / low
62°17° / 45°7°
Wind
17 mph27 km/h, gusts 37 mph59 km/h

10 days15 days30 days

The outlook

Today
Dry, high 64°, low 34°.
Tomorrow
Dry, high 67°, low 39°, warming up.
Monday
Dry, high 69°, low 45°.
Rest of week
Mostly dry, highs 64–73°.

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

For your home

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

Heating this week

About 53% less heating than a typical week.

This week 32Typical 68

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 19 hours are near freezing and damp, when outdoor units defrost more often.

Comfort

Dry air outside (dew point 34°F).

Open the windows?

Sun, 12:00 PM–6:00 PM

Good stretch to open the windows.

Is this typical?

Philadelphia Franklin Institute · official normals 1991–2020 · records 1940–2026

Oct 24, today vs a typical year

Today’s expected high is about typical for the date.

Last 7 days vs normal

—SunOct 18
—MonOct 19
—TueOct 20
—WedOct 21
—ThuOct 22
—FriOct 23
—SatOct 24

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

Sun & moon

Sun

Daylight: 10 h 47 min; Losing 2 min 25 s a day; shortest Dec 21, 1 h 28 min less
Golden hour: 5:31–6:25 PM; Morning 7:04–7:59 AM
Blue hour: 6:25–6:36 PM; Morning 6:54–7:04 AM; first light 6:54 AM

Stars tonight? Fair

Clear 6:36 PM–6:55 AM, but the moon is 99% lit and up.

Moon

Waxing gibbous

98% lit · growing

Today: sets 5:33 AM · rises 5:05 PM
Full moon: Oct 26
New moon: Nov 9

Looking north from Norristown.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