Frost Advisory
Starts in 8 h 50 min
When
From midnight tonight to 9 AM EDT Sunday.
Where
Portions of central, northern, and southern New Jersey.
Issued for this forecast zone · National Weather Service Mount Holly NJ
What, impacts and precautionsHide details
What
Temperatures as low as 32 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; Eastern Monmouth; Mercer; Salem; Gloucester; Camden; Northwestern Burlington; Ocean; Cumberland; Atlantic; Cape May; Southeastern Burlington
See it on weather.gov (opens in a new tab)

Observed 2:50 PM EDT at KTTN

Princeton Junction, NJ weather

Sunny and 61°16°, jacket by 7 PM.

Forecasts agree

Now 61°16°

Sunny

Wind: 3 mph5 km/h; From the south-southwest. Light through 3 AM
Dew point: 28°−2°; Dry · up to 37°3° by 7 PM (comfortable)
UV tomorrow: 4Moderate; Moderate 11 AM–4 PM · peak 4
Air quality: 30Good; Ozone · tomorrow moderate
Pressure: 30.52 inHg1034 hPa; Falling · −0.05 inHg−1.6 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 8 PM
Low 34°1° tomorrow at 6 AM
Above 50°10° tomorrow by 10 AM

This afternoonNear 62°17° · Partly cloudy
TonightDown to 35°2° by 4 AM · Clear
Tomorrow morningUp to 57°14° by 11 AM · Clear
Tomorrow afternoonUp to 66°19° by 4 PM · Clear
Tomorrow nightDown to 37°3° by 5 AM · Clear
Monday morningUp to 58°14° by 11 AM · Clear
Monday afternoonUp to 67°19° 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	Mostly sunny	62°17° (likely 60°16° to 62°17°)	62°17°	0%	0 mph0 km/h, gusts 3 mph4 km/h	36%	28%	2
Sat 4p	Mostly sunny	63°17° (likely 60°16° to 63°17°)	63°17°	0%	0 mph0 km/h, gusts 2 mph3 km/h	34%	20%	1
Sat 5p	Sunny	61°16° (likely 59°15° to 61°16°)	61°16°	0%	0 mph0 km/h, gusts 2 mph3 km/h	36%	53%	0
Sat 6p	Clear	58°14° (likely 55°13° to 58°14°)	58°14°	0%	0 mph0 km/h, gusts 2 mph4 km/h	44%	50%	0
Sat 7p	Clear	53°12° (likely 51°11° to 53°12°)	53°12°	0%	0 mph0 km/h, gusts 2 mph4 km/h	54%	60%	0
Sat 8p	Mostly clear	47°8° (likely 47°8° to 52°11°)	47°8°	0%	0 mph0 km/h, gusts 2 mph4 km/h	68%	35%	0
Sat 9p	Clear	45°7° (likely 45°7° to 50°10°)	45°7°	0%	0 mph0 km/h, gusts 2 mph4 km/h	73%	16%	0
Sat 10p	Clear	43°6° (likely 43°6° to 49°9°)	43°6°	0%	0 mph0 km/h, gusts 2 mph3 km/h	76%	26%	0
Sat 11p	Clear	41°5° (likely 41°5° to 45°7°)	41°5°	0%	0 mph0 km/h, gusts 5 mph7 km/h	79%	14%	0
Sun 12a	Clear	40°4° (likely 40°4° to 43°6°)	40°4°	0%	0 mph0 km/h, gusts 4 mph7 km/h	82%	2%	0
Sun 1a	Clear	39°4° (likely 39°4° to 42°6°)	39°4°	0%	0 mph0 km/h, gusts 5 mph8 km/h	85%	0%	0
Sun 2a	Clear	38°3° (likely 38°3° to 42°6°)	38°3°	0%	0 mph0 km/h, gusts 4 mph6 km/h	85%	0%	0
Sun 3a	Clear	36°2° (likely 36°2° to 41°5°)	36°2°	0%	0 mph0 km/h, gusts 3 mph5 km/h	92%	0%	0
Sun 4a	Clear	35°2° (likely 35°2° to 41°5°)	35°2°	0%	0 mph0 km/h, gusts 3 mph5 km/h	92%	0%	0
Sun 5a	Clear	35°2° (likely 35°2° to 40°4°)	35°2°	0%	0 mph0 km/h, gusts 3 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 4 mph7 km/h	92%	0%	0
Sun 7a	Sunny	34°1° (likely 34°1° to 40°4°)	34°1°	0%	0 mph0 km/h, gusts 4 mph6 km/h	92%	0%	0
Sun 8a	Sunny	35°2° (likely 35°2° to 38°3°)	35°2°	0%	0 mph0 km/h, gusts 2 mph4 km/h	92%	0%	0
Sun 9a	Sunny	42°6° (likely 41°5° to 44°7°)	42°6°	0%	0 mph0 km/h, gusts 3 mph5 km/h	82%	0%	1
Sun 10a	Sunny	51°11° (likely 50°10° to 52°11°)	51°11°	0%	0 mph0 km/h, gusts 5 mph8 km/h	61%	0%	2
Sun 11a	Sunny	57°14° (likely 56°13° to 59°15°)	57°14°	0%	0 mph0 km/h, gusts 6 mph10 km/h	51%	0%	3
Sun 12p	Sunny	60°16° (likely 59°15° to 63°17°)	60°16°	0%	0 mph0 km/h, gusts 9 mph15 km/h	44%	1%	4
Sun 1p	Sunny	64°18° (likely 61°16° to 65°18°)	64°18°	0%	0 mph0 km/h, gusts 9 mph14 km/h	37%	1%	4
Sun 2p	Sunny	65°18° (likely 62°17° to 66°19°)	65°18°	0%	0 mph0 km/h, gusts 8 mph13 km/h	34%	0%	4
Sun 3p	Sunny	65°18° (likely 63°17° to 66°19°)	65°18°	0%	0 mph0 km/h, gusts 8 mph12 km/h	34%	0%	3
Sun 4p	Sunny	66°19° (likely 63°17° to 66°19°)	66°19°	0%	0 mph0 km/h, gusts 7 mph11 km/h	32%	0%	2
Sun 5p	Sunny	65°18° (likely 61°16° to 65°18°)	65°18°	0%	0 mph0 km/h, gusts 7 mph11 km/h	35%	0%	1
Sun 6p	Clear	60°16° (likely 56°13° to 60°16°)	60°16°	0%	0 mph0 km/h, gusts 5 mph7 km/h	44%	0%	0
Sun 7p	Clear	55°13° (likely 52°11° to 55°13°)	55°13°	0%	0 mph0 km/h, gusts 5 mph8 km/h	55%	0%	0
Sun 8p	Clear	49°9° (likely 49°9° to 52°11°)	49°9°	0%	0 mph0 km/h, gusts 7 mph11 km/h	71%	0%	0
Sun 9p	Clear	46°8° (likely 46°8° to 50°10°)	46°8°	0%	0 mph0 km/h, gusts 6 mph10 km/h	76%	0%	0
Sun 10p	Clear	44°7° (likely 44°7° to 48°9°)	44°7°	0%	0 mph0 km/h, gusts 6 mph10 km/h	79%	0%	0
Sun 11p	Clear	42°6° (likely 42°6° to 46°8°)	42°6°	0%	0 mph0 km/h, gusts 6 mph10 km/h	82%	0%	0
Mon 12a	Clear	41°5° (likely 41°5° to 45°7°)	41°5°	0%	0 mph0 km/h, gusts 7 mph11 km/h	85%	1%	0
Mon 1a	Clear	40°4° (likely 40°4° to 44°7°)	40°4°	0%	0 mph0 km/h, gusts 8 mph12 km/h	89%	2%	0
Mon 2a	Clear	39°4° (likely 38°3° to 43°6°)	39°4°	0%	0 mph0 km/h, gusts 6 mph10 km/h	92%	2%	0
Mon 3a	Clear	38°3° (likely 37°3° to 42°6°)	38°3°	0%	0 mph0 km/h, gusts 6 mph10 km/h	92%	1%	0
Mon 4a	Clear	38°3° (likely 36°2° to 42°6°)	38°3°	0%	0 mph0 km/h, gusts 7 mph11 km/h	92%	2%	0
Mon 5a	Clear	37°3° (likely 34°1° to 41°5°)	37°3°	0%	0 mph0 km/h, gusts 7 mph12 km/h	92%	4%	0
Mon 6a	Clear	36°2° (likely 33°1° to 41°5°)	36°2°	0%	0 mph0 km/h, gusts 7 mph11 km/h	92%	15%	0
Mon 7a	Sunny	36°2° (likely 33°1° to 42°6°)	36°2°	0%	0 mph0 km/h, gusts 6 mph10 km/h	92%	13%	0
Mon 8a	Sunny	38°3° (likely 35°2° to 43°6°)	38°3°	0%	0 mph0 km/h, gusts 7 mph12 km/h	100%	16%	0
Mon 9a	Sunny	44°7° (likely 40°4° to 50°10°)	44°7°	0%	0 mph0 km/h, gusts 8 mph13 km/h	89%	17%	1
Mon 10a	Mostly sunny	51°11° (likely 49°9° to 56°13°)	51°11°	0%	5 mph8 km/h from W, gusts 11 mph17 km/h	77%	10%	2
Mon 11a	Mostly sunny	58°14° (likely 57°14° to 60°16°)	58°14°	0%	5 mph8 km/h from W, gusts 12 mph19 km/h	64%	12%	3
Mon 12p	Sunny	62°17° (likely 61°16° to 63°17°)	62°17°	0%	5 mph8 km/h from W, gusts 13 mph20 km/h	56%	2%	4
Mon 1p	Sunny	65°18° (likely 64°18° to 66°19°)	65°18°	0%	5 mph8 km/h from W, gusts 13 mph20 km/h	48%	3%	4
Mon 2p	Sunny	67°19° (likely 65°18° to 68°20°)	67°19°	0%	5 mph8 km/h from W, gusts 13 mph21 km/h	45%	0%	4

Days ahead

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

Today, Oct 24. Cloudy. High 64°18°, low 33°1°. Typical 62°17° / 43°6°. Dry. Forecasts agree.
1. Afternoon
  noon–6 PM
  Mostly sunny, 63°17°
  Dry
2. Evening
  6 PM–midnight
  Clear, 47°8°
  Dry
3. Overnight
  midnight–6 AM
  Clear, 35°2°
  Dry
Official NWS forecast
Today: Sunny, with a high near 64. Wind around 0 mph.
Tonight: Areas of frost after 10pm. Clear, with a low around 33. Wind around 0 mph.
Forecasts agreeIndependent forecasts are close; the range is narrow.
High, likely
61°16°–64°18°
Low, likely
33°1°–37°3°
Typical high / low
62°17° / 43°6°
Wind
6 mph9 km/h
UV peak
4
Tomorrow, Oct 25. Sunny. High 67°19°, low 36°2°. Typical 62°17° / 42°6°. Dry. Mostly 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, 49°9°
  Dry
4. Overnight
  midnight–6 AM
  Clear, 37°3°
  Dry
Official NWS forecast
Day: Areas of frost before 9am. Sunny, with a high near 67. Northwest wind around 0 mph.
Night: Clear, with a low around 36. Northwest wind around 0 mph.
Mostly agreeIndependent forecasts are fairly close; small surprises are possible.
High, likely
63°17°–67°19°
Low, likely
35°2°–37°3°
Typical high / low
62°17° / 42°6°
Wind
6 mph9 km/h
UV peak
4
Monday, Oct 26. Sunny. High 69°21°, low 45°7°. Typical 62°17° / 42°6°. Dry. Forecasts agree.
1. Morning
  6 AM–noon
  Sunny, 38°3°
  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, 50°10°
  Dry
Official NWS forecast
Day: Sunny, with a high near 69. West wind 0 to 5 mph.
Night: Mostly clear, with a low around 45.
Forecasts agreeIndependent forecasts are close; the range is narrow.
High, likely
66°19°–69°21°
Low, likely
33°1°–45°7°
Typical high / low
62°17° / 42°6°
Wind
9 mph15 km/h, gusts 18 mph29 km/h
UV peak
4
Tuesday, Oct 27. Mostly sunny. High 63°17°, low 37°3°. Typical 61°16° / 42°6°. Dry. Mostly agree.
1. Morning
  6 AM–noon
  Sunny, 47°8°
  Dry
2. Afternoon
  noon–6 PM
  Sunny, 61°16°
  Dry
3. Evening
  6 PM–midnight
  Clear, 49°9°
  Dry
4. Overnight
  midnight–6 AM
  Clear, 40°4°
  Dry
Hours this far out come from computer models only.
Official NWS forecast
Day: Sunny, with a high near 63.
Night: Mostly clear, with a low around 37.
Mostly agreeIndependent forecasts are fairly close; small surprises are possible.
High, likely
59°15°–64°18°
Low, likely
37°3°–47°8°
Typical high / low
61°16° / 42°6°
Wind
10 mph16 km/h, gusts 24 mph38 km/h
UV peak
4
Wednesday, Oct 28. Partly sunny. High 62°17°, low 41°5°. Typical 61°16° / 41°5°. Dry. Mostly agree.
1. Morning
  6 AM–noon
  Sunny, 40°4°
  Dry
2. Afternoon
  noon–6 PM
  Cloudy, 61°16°
  Dry
3. Evening
  6 PM–midnight
  Mostly clear, 51°11°
  Dry
4. Overnight
  midnight–6 AM
  Cloudy, 45°7°
  Dry
Hours this far out come from computer models only.
Official NWS forecast
Day: Mostly sunny, with a high near 62.
Night: Mostly cloudy, with a low around 41.
Mostly agreeIndependent forecasts are fairly close; small surprises are possible.
High, likely
58°14°–63°17°
Low, likely
35°2°–41°5°
Typical high / low
61°16° / 41°5°
Wind
9 mph15 km/h, gusts 14 mph23 km/h
UV peak
3
Thursday, Oct 29. Partly sunny. High 68°20°, low 47°8°. Typical 61°16° / 41°5°. Dry. Mostly agree.
1. Morning
  6 AM–noon
  Sunny, 44°7°
  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, 48°9°
  Dry
Hours this far out come from computer models only.
Official NWS forecast
Day: Mostly sunny, with a high near 68.
Night: Mostly clear, with a low around 47.
Mostly agreeIndependent forecasts are fairly close; small surprises are possible.
High, likely
65°18°–69°21°
Low, likely
41°5°–47°8°
Typical high / low
61°16° / 41°5°
Wind
8 mph13 km/h, gusts 30 mph48 km/h
UV peak
4
Friday, Oct 30. Mostly sunny. High 71°22°, low 45°7°. Typical 60°16° / 41°5°. Dry. Forecasts agree.
1. Morning
  6 AM–noon
  Sunny, 48°9°
  Dry
2. Afternoon
  noon–6 PM
  Sunny, 73°23°
  Dry
3. Evening
  6 PM–midnight
  Clear, 59°15°
  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 71.
Night: Mostly clear, with a low around 45.
Forecasts agreeIndependent forecasts are close; the range is narrow.
High, likely
71°22°–74°23°
Low, likely
45°7°–50°10°
Typical high / low
60°16° / 41°5°
Wind
7 mph11 km/h, gusts 26 mph42 km/h
UV peak
4
Saturday, Oct 31. Cloudy. High 70°21°, low 48°9°. Typical 60°16° / 40°4°. Dry. Forecasts differ.
1. Morning
  6 AM–noon
  Sunny, 48°9°
  Dry
2. Afternoon
  noon–6 PM
  Sunny, 71°22°
  Dry
3. Evening
  6 PM–midnight
  Cloudy, 58°14°
  Dry
4. Overnight
  midnight–6 AM
  Cloudy, 54°12°
  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°–73°23°
Low, likely
44°7°–53°12°
Typical high / low
60°16° / 40°4°
Wind
9 mph14 km/h, gusts 25 mph40 km/h
UV peak
4
Sunday, Nov 1. Cloudy. High 69°21°, low 53°12°. Typical 60°16° / 40°4°. Rain 0.01 in0.3 mm, 30% chance. Forecasts differ.
1. Morning
  6 AM–noon
  Cloudy, 55°13°
  Dry
2. Afternoon
  noon–6 PM
  Cloudy, 68°20°
  Dry
3. Evening
  6 PM–midnight
  Drizzle, 63°17°
  30% chance · 0.01 in0.4 mm
4. Overnight
  midnight–6 AM
  Drizzle, 62°16°
  30% chance · 0.2 in5.2 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
64°18°–73°23°
Low, likely
52°11°–55°13°
Typical high / low
60°16° / 40°4°
Wind
10 mph16 km/h, gusts 21 mph33 km/h
UV peak
2
Monday, Nov 2. Drizzle. High 72°22°, low 60°16°. Typical 59°15° / 40°4°. Rain 0.42 in11 mm, 30% chance. Forecasts differ.
1. Morning
  6 AM–noon
  Drizzle, 64°18°
  30% chance · 0.09 in2.3 mm
2. Afternoon
  noon–6 PM
  Showers, 72°22°
  20% chance · 0.1 in2.4 mm
3. Evening
  6 PM–midnight
  Showers, 68°20°
  20% chance · 0.1 in2.5 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
66°19°–78°26°
Low, likely
58°14°–66°19°
Typical high / low
59°15° / 40°4°
Wind
18 mph28 km/h, gusts 38 mph61 km/h

10 days15 days30 days

The outlook

Today
Dry, high 64°, low 33°.
Tomorrow
Dry, high 67°, low 36°, warming up.
Monday
Dry, high 69°, low 45°.
Rest of week
Mostly dry, highs 62–72°.

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

Assunpink Creek at Trenton

9.6 mi

Below flood stage

Level: 2.9 ft
Flow: 68 cfs

Forecast peak 2.9 ft Sat 8 PM

Reading from Sat 2 PM · NWS gauge page

Millstone River at Blackwells Mills

11 mi

Below flood stage

Level: 1.9 ft
Flow: 157 cfs

Forecast peak 1.9 ft Sat 8 PM

Reading from Sat 1:15 PM · NWS gauge page

Delaware River at Trenton

11 mi

Below flood stage

Level: 8.6 ft
Flow: 4,290 cfs

Forecast peak 8.6 ft Sat 8 PM

Reading from Sat 1:15 PM · NWS gauge page

Stony Brook at Princeton

3.2 mi

Below flood stage

Level: 1.6 ft
Flow: 15 cfs

Reading from Sat 1:30 PM · NWS gauge page

For your home

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

Heating this week

About 65% less heating than a typical week.

This week 33Typical 95

Heating degree days, base 65°F

Heat-pump hours, next 7 days

h below 47°F: 27
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 20 hours are near freezing and damp, when outdoor units defrost more often.

Comfort

Dry air outside (dew point 28°F).

Open the windows?

Today, 4:00 PM–5:00 PM

Good stretch to open the windows.

Is this typical?

Trenton-Mercer Airport · official normals 1991–2020 · records 1865–2026

Oct 24, today vs a typical year

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

Last 7 days vs normal

On average 2°1° colder than normal (daily mean temperature).

−7°−4°SunOct 18
−3°−2°MonOct 19
+2°+1°TueOct 20
+2°+1°WedOct 21
+1°ThuOct 22
−3°−2°FriOct 23
—SatOct 24

Princeton Junction weather by month: normals, records, snow and freeze dates

Sun & moon

Sun

Daylight: 10 h 46 min; Losing 2 min 30 s a day; shortest Dec 21, 1 h 29 min less
Golden hour: 5:27–6:22 PM; Morning 7:02–7:56 AM
Blue hour: 6:22–6:33 PM; Morning 6:51–7:02 AM; first light 6:51 AM

Stars tonight? Fair

Mostly clear 11 PM–6:52 AM, but the moon is 99% lit and up.

Moon

Waxing gibbous

97% lit · growing

Today: sets 5:30 AM · rises 5:02 PM
Full moon: Oct 26
New moon: Nov 9

Looking northwest from Princeton Junction.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

Princeton Junction, NJ weather

Next 2 hours

Next 48 hours

Days ahead

The outlook

Today

Tomorrow

Monday

Rest of week

What changed since yesterday

Radar

Rivers

Assunpink Creek at Trenton

Millstone River at Blackwells Mills

Delaware River at Trenton

Stony Brook at Princeton

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