Observed 11:30 AM EDT at KTTN

Princeton, NJ weather

Sunny and 55°13°, jacket by 7 PM.

Mostly agree

Now 55°13°

Sunny

Wind: Calm; Light through 11 PM
Dew point: 36°2°; Comfortable
UV index: 2Low; Moderate 12–3 PM · peak 3
Air quality: 43Good; PM2.5 (fine particles) · tomorrow moderate
Pressure: 30.57 inHg1035 hPa; Steady over the last 3 h

No precipitation expected in the next 2 hours.

From forecast models

Next 48 hours

3°2° cooler than this time yesterday (56°13° then, 53°12° now)

Good hours for

High 62°17° today at 4 PM
Below 50°10° tonight after 8 PM
Low 35°2° tomorrow at 6 AM
Above 50°10° tomorrow by 10 AM

This afternoonUp to 62°17° by 4 PM · Clear
TonightDown to 36°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 38°3° by 5 AM · Clear
Monday morningUp to 51°11° by 10 AM · 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 11a	Sunny	52°11° (likely 52°11° to 54°12°)	52°11°	0%	0 mph0 km/h, gusts 5 mph8 km/h	54%	28%	2
Sat 12p	Mostly sunny	56°13° (likely 55°13° to 58°14°)	56°13°	0%	0 mph0 km/h, gusts 4 mph6 km/h	47%	33%	3
Sat 1p	Cloudy	59°15° (likely 58°14° to 60°16°)	59°15°	0%	0 mph0 km/h, gusts 3 mph6 km/h	40%	55%	3
Sat 2p	Mostly sunny	61°16° (likely 59°15° to 62°17°)	61°16°	0%	0 mph0 km/h, gusts 3 mph5 km/h	36%	26%	3
Sat 3p	Sunny	61°16° (likely 60°16° to 62°17°)	61°16°	0%	0 mph0 km/h, gusts 2 mph4 km/h	36%	16%	2
Sat 4p	Mostly sunny	62°17° (likely 60°16° to 62°17°)	62°17°	0%	0 mph0 km/h, gusts 2 mph4 km/h	33%	14%	1
Sat 5p	Sunny	61°16° (likely 59°15° to 61°16°)	61°16°	0%	0 mph0 km/h, gusts 2 mph4 km/h	36%	1%	0
Sat 6p	Clear	58°14° (likely 55°13° to 58°14°)	58°14°	0%	0 mph0 km/h, gusts 2 mph3 km/h	44%	0%	0
Sat 7p	Clear	53°12° (likely 51°11° to 53°12°)	53°12°	0%	0 mph0 km/h, gusts 2 mph3 km/h	54%	0%	0
Sat 8p	Clear	48°9° (likely 48°9° to 51°11°)	48°9°	0%	0 mph0 km/h, gusts 2 mph4 km/h	63%	0%	0
Sat 9p	Clear	46°8° (likely 45°7° to 50°10°)	46°8°	0%	0 mph0 km/h, gusts 2 mph3 km/h	68%	1%	0
Sat 10p	Clear	44°7° (likely 44°7° to 49°9°)	44°7°	0%	0 mph0 km/h, gusts 2 mph3 km/h	73%	4%	0
Sat 11p	Clear	42°6° (likely 42°6° to 48°9°)	42°6°	0%	0 mph0 km/h, gusts 3 mph4 km/h	76%	0%	0
Sun 12a	Clear	40°4° (likely 40°4° to 45°7°)	40°4°	0%	0 mph0 km/h, gusts 3 mph5 km/h	79%	2%	0
Sun 1a	Clear	39°4° (likely 39°4° to 45°7°)	39°4°	0%	0 mph0 km/h, gusts 4 mph6 km/h	82%	0%	0
Sun 2a	Clear	39°4° (likely 38°3° to 44°7°)	39°4°	0%	0 mph0 km/h, gusts 4 mph6 km/h	79%	0%	0
Sun 3a	Clear	37°3° (likely 37°3° to 44°7°)	37°3°	0%	0 mph0 km/h, gusts 4 mph7 km/h	85%	1%	0
Sun 4a	Clear	36°2° (likely 36°2° to 44°7°)	36°2°	0%	0 mph0 km/h, gusts 4 mph6 km/h	85%	0%	0
Sun 5a	Clear	36°2° (likely 35°2° to 42°6°)	36°2°	0%	0 mph0 km/h, gusts 4 mph6 km/h	85%	0%	0
Sun 6a	Clear	35°2° (likely 35°2° to 40°4°)	35°2°	0%	0 mph0 km/h, gusts 5 mph8 km/h	89%	0%	0
Sun 7a	Sunny	35°2° (likely 34°1° to 40°4°)	35°2°	0%	0 mph0 km/h, gusts 5 mph7 km/h	89%	0%	0
Sun 8a	Sunny	36°2° (likely 35°2° to 41°5°)	36°2°	0%	0 mph0 km/h, gusts 4 mph6 km/h	89%	0%	0
Sun 9a	Sunny	42°6° (likely 41°5° to 46°8°)	42°6°	0%	0 mph0 km/h, gusts 4 mph6 km/h	79%	0%	1
Sun 10a	Sunny	51°11° (likely 50°10° to 52°11°)	51°11°	0%	0 mph0 km/h, gusts 5 mph7 km/h	61%	0%	2
Sun 11a	Sunny	57°14° (likely 57°14° to 58°14°)	57°14°	0%	0 mph0 km/h, gusts 6 mph9 km/h	49%	0%	3
Sun 12p	Sunny	60°16° (likely 60°16° to 62°17°)	60°16°	0%	0 mph0 km/h, gusts 9 mph14 km/h	42%	1%	4
Sun 1p	Sunny	63°17° (likely 61°16° to 64°18°)	63°17°	0%	0 mph0 km/h, gusts 8 mph13 km/h	36%	0%	4
Sun 2p	Sunny	64°18° (likely 62°17° to 65°18°)	64°18°	0%	0 mph0 km/h, gusts 8 mph12 km/h	34%	0%	4
Sun 3p	Sunny	65°18° (likely 63°17° to 66°19°)	65°18°	0%	0 mph0 km/h, gusts 7 mph11 km/h	33%	0%	3
Sun 4p	Sunny	66°19° (likely 63°17° to 66°19°)	66°19°	0%	0 mph0 km/h, gusts 6 mph10 km/h	32%	0%	2
Sun 5p	Sunny	64°18° (likely 62°17° to 64°18°)	64°18°	0%	0 mph0 km/h, gusts 7 mph11 km/h	37%	0%	1
Sun 6p	Clear	60°16° (likely 56°13° to 60°16°)	60°16°	0%	0 mph0 km/h, gusts 5 mph9 km/h	46%	0%	0
Sun 7p	Clear	55°13° (likely 52°11° to 55°13°)	55°13°	0%	0 mph0 km/h, gusts 5 mph7 km/h	55%	0%	0
Sun 8p	Clear	49°9° (likely 49°9° to 53°12°)	49°9°	0%	0 mph0 km/h, gusts 7 mph11 km/h	68%	0%	0
Sun 9p	Clear	47°8° (likely 47°8° to 51°11°)	47°8°	0%	0 mph0 km/h, gusts 8 mph12 km/h	74%	0%	0
Sun 10p	Clear	45°7° (likely 45°7° to 50°10°)	45°7°	0%	0 mph0 km/h, gusts 7 mph11 km/h	76%	0%	0
Sun 11p	Clear	43°6° (likely 43°6° to 48°9°)	43°6°	0%	0 mph0 km/h, gusts 8 mph13 km/h	79%	0%	0
Mon 12a	Clear	42°6° (likely 42°6° to 47°8°)	42°6°	0%	0 mph0 km/h, gusts 9 mph14 km/h	82%	0%	0
Mon 1a	Clear	41°5° (likely 40°4° to 47°8°)	41°5°	0%	0 mph0 km/h, gusts 10 mph15 km/h	82%	0%	0
Mon 2a	Clear	40°4° (likely 39°4° to 47°8°)	40°4°	0%	0 mph0 km/h, gusts 9 mph14 km/h	85%	0%	0
Mon 3a	Clear	39°4° (likely 38°3° to 45°7°)	39°4°	0%	0 mph0 km/h, gusts 8 mph13 km/h	89%	0%	0
Mon 4a	Clear	39°4° (likely 37°3° to 45°7°)	39°4°	0%	0 mph0 km/h, gusts 9 mph14 km/h	89%	0%	0
Mon 5a	Clear	38°3° (likely 36°2° to 44°7°)	38°3°	0%	0 mph0 km/h, gusts 9 mph14 km/h	92%	0%	0
Mon 6a	Clear	37°3° (likely 34°1° to 44°7°)	37°3°	0%	0 mph0 km/h, gusts 9 mph15 km/h	92%	0%	0
Mon 7a	Sunny	37°3° (likely 34°1° to 43°6°)	34°1°	0%	5 mph8 km/h from W, gusts 8 mph14 km/h	92%	11%	0
Mon 8a	Sunny	39°4° (likely 35°2° to 44°7°)	37°3°	0%	5 mph8 km/h from W, gusts 8 mph14 km/h	100%	13%	0
Mon 9a	Sunny	44°7° (likely 43°6° to 50°10°)	42°6°	0%	5 mph8 km/h from W, gusts 7 mph12 km/h	89%	2%	1
Mon 10a	Sunny	51°11° (likely 51°11° to 55°13°)	51°11°	0%	5 mph8 km/h from W, gusts 10 mph17 km/h	74%	10%	2

Days ahead

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

Today, Oct 24. Cloudy. High 63°17°, low 35°2°. Typical 62°17° / 43°6°. Dry. Mostly agree.
1. Afternoon
  noon–6 PM
  Sunny, 62°17°
  Dry
2. Evening
  6 PM–midnight
  Clear, 48°9°
  Dry
3. Overnight
  midnight–6 AM
  Clear, 36°2°
  Dry
Official NWS forecast
Today: Sunny, with a high near 63. North wind around 0 mph.
Tonight: Areas of frost after 10pm. Clear, with a low around 35. Northwest wind around 0 mph.
Mostly agreeIndependent forecasts are fairly close; small surprises are possible.
High, likely
60°16°–63°17°
Low, likely
33°1°–38°3°
Typical high / low
62°17° / 43°6°
Wind
6 mph10 km/h
UV peak
4
Tomorrow, Oct 25. Sunny. High 67°19°, low 37°3°. Typical 62°17° / 42°6°. Dry. Mostly agree.
1. Morning
  6 AM–noon
  Sunny, 36°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, 38°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 37. West wind around 0 mph.
Mostly agreeIndependent forecasts are fairly close; small surprises are possible.
High, likely
63°17°–67°19°
Low, likely
34°1°–40°4°
Typical high / low
62°17° / 42°6°
Wind
6 mph10 km/h, gusts 11 mph18 km/h
UV peak
4
Monday, Oct 26. Sunny. High 69°21°, low 46°8°. Typical 62°17° / 42°6°. Dry. Mostly 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, 50°10°
  Dry
Hours this far out come from computer models only.
Official NWS forecast
Day: Sunny, with a high near 69. West wind 0 to 5 mph.
Night: Mostly clear, with a low around 46.
Mostly agreeIndependent forecasts are fairly close; small surprises are possible.
High, likely
66°19°–69°21°
Low, likely
34°1°–46°8°
Typical high / low
62°17° / 42°6°
Wind
9 mph15 km/h, gusts 17 mph27 km/h
UV peak
4
Tuesday, Oct 27. Mostly sunny. High 62°17°, low 38°3°. Typical 61°16° / 42°6°. Dry. Mostly agree.
1. Morning
  6 AM–noon
  Sunny, 48°9°
  Dry
2. Afternoon
  noon–6 PM
  Sunny, 62°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 62.
Night: Mostly clear, with a low around 38.
Mostly agreeIndependent forecasts are fairly close; small surprises are possible.
High, likely
59°15°–64°18°
Low, likely
38°3°–47°8°
Typical high / low
61°16° / 42°6°
Wind
9 mph14 km/h, gusts 25 mph40 km/h
UV peak
4
Wednesday, Oct 28. Partly sunny. High 61°16°, low 42°6°. Typical 61°16° / 41°5°. Dry. Mostly agree.
1. Morning
  6 AM–noon
  Sunny, 39°4°
  Dry
2. Afternoon
  noon–6 PM
  Cloudy, 60°16°
  Dry
3. Evening
  6 PM–midnight
  Cloudy, 51°10°
  Dry
4. Overnight
  midnight–6 AM
  Mostly clear, 44°7°
  Dry
Hours this far out come from computer models only.
Official NWS forecast
Day: Mostly sunny, with a high near 61.
Night: Mostly cloudy, with a low around 42.
Mostly agreeIndependent forecasts are fairly close; small surprises are possible.
High, likely
59°15°–63°17°
Low, likely
34°1°–42°6°
Typical high / low
61°16° / 41°5°
Wind
9 mph14 km/h
UV peak
4
Thursday, Oct 29. Partly sunny. High 67°19°, low 48°9°. Typical 61°16° / 41°5°. Dry. Mostly agree.
1. Morning
  6 AM–noon
  Sunny, 44°6°
  Dry
2. Afternoon
  noon–6 PM
  Sunny, 66°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 67.
Night: Mostly clear, with a low around 48.
Mostly agreeIndependent forecasts are fairly close; small surprises are possible.
High, likely
64°18°–68°20°
Low, likely
41°5°–48°9°
Typical high / low
61°16° / 41°5°
Wind
8 mph13 km/h, gusts 29 mph47 km/h
UV peak
4
Friday, Oct 30. Mostly sunny. High 70°21°, low 46°8°. Typical 60°16° / 41°5°. Dry. Forecasts agree.
1. Morning
  6 AM–noon
  Sunny, 47°8°
  Dry
2. Afternoon
  noon–6 PM
  Sunny, 71°22°
  Dry
3. Evening
  6 PM–midnight
  Clear, 58°14°
  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 70.
Night: Mostly clear, with a low around 46.
Forecasts agreeIndependent forecasts are close; the range is narrow.
High, likely
70°21°–73°23°
Low, likely
43°6°–50°10°
Typical high / low
60°16° / 41°5°
Wind
13 mph20 km/h, gusts 28 mph44 km/h
UV peak
4
Saturday, Oct 31. Cloudy. High 69°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, 68°20°
  Dry
3. Evening
  6 PM–midnight
  Cloudy, 57°14°
  Dry
4. Overnight
  midnight–6 AM
  Partly cloudy, 48°9°
  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
60°16°–73°23°
Low, likely
43°6°–53°12°
Typical high / low
60°16° / 40°4°
Wind
12 mph20 km/h, gusts 24 mph39 km/h
UV peak
3
Sunday, Nov 1. Cloudy. High 66°19°, low 48°9°. Typical 60°16° / 40°4°. Rain, 20% chance. Forecasts differ.
1. Morning
  6 AM–noon
  Mostly sunny, 48°9°
  Dry
2. Afternoon
  noon–6 PM
  Cloudy, 65°18°
  Dry
3. Evening
  6 PM–midnight
  Cloudy, 57°14°
  20% chance
4. Overnight
  midnight–6 AM
  Partly cloudy, 54°12°
  30% chance · 0.01 in0.3 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
56°13°–71°22°
Low, likely
42°6°–53°12°
Typical high / low
60°16° / 40°4°
Wind
10 mph16 km/h, gusts 19 mph30 km/h
UV peak
4
Monday, Nov 2. Cloudy. High 65°18°, low 54°12°. Typical 59°15° / 40°4°. Rain 0.09 in2.3 mm, 30% chance. Forecasts differ.
1. Morning
  6 AM–noon
  Cloudy, 56°13°
  30% chance
2. Afternoon
  noon–6 PM
  Cloudy, 67°19°
  20% chance
3. Evening
  6 PM–midnight
  Cloudy, 59°15°
  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
53°12°–72°22°
Low, likely
45°7°–59°15°
Typical high / low
59°15° / 40°4°
Wind
11 mph17 km/h, gusts 22 mph35 km/h
UV peak
2

10 days15 days30 days

The outlook

Today
Dry, high 63°, low 35°.
Tomorrow
Dry, high 67°, low 37°, warming up.
Monday
Dry, high 69°, low 46°.
Rest of week
Mostly dry, highs 61–70°.

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

Millstone River at Blackwells Mills

9.4 mi

Below flood stage

Level: 1.9 ft
Flow: 157 cfs

Forecast peak 1.9 ft Sat 2 PM

Reading from Sat 10:15 AM · NWS gauge page

Assunpink Creek at Trenton

10 mi

Below flood stage

Level: 2.9 ft
Flow: 64 cfs

Forecast peak 2.9 ft Sat 2 PM

Reading from Sat 10:15 AM · NWS gauge page

Delaware River at Trenton

11 mi

Below flood stage

Level: 8.6 ft
Flow: 4,330 cfs

Forecast peak 8.6 ft Sat 2 PM

Reading from Sat 10:15 AM · NWS gauge page

Stony Brook at Princeton

1.9 mi

Below flood stage

Level: 1.6 ft
Flow: 15 cfs

Reading from Sat 10:30 AM · 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: 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 16 hours are near freezing and damp, when outdoor units defrost more often.

Comfort

Dry air outside (dew point 36°F).

Open the windows?

Today, 2:00 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 about typical for the date.

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

Sun & moon

Sun

Daylight: 10 h 46 min; Losing 2 min 25 s a day; shortest Dec 21, 1 h 29 min less
Golden hour: 5:28–6:22 PM; Morning 7:02–7:57 AM
Blue hour: 6:22–6:33 PM; Morning 6:51–7:02 AM; first light 6:51 AM

Stars tonight? Fair

Clear 6:33 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.Skyline from USGS elevation data, heights drawn up to 6× taller. Sky, sun and moon as they are now.

Princeton, NJ weather

Next 2 hours

Next 48 hours

Days ahead

The outlook

Today

Tomorrow

Monday

Rest of week

What changed since yesterday

Radar

Rivers

Millstone River at Blackwells Mills

Assunpink Creek at Trenton

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