Princeton, NJ Weather

Mercer County8:52 AM EDT40.35°N, 74.66°WElevation 203 ft
Frost Advisory until 9:00 AM Sat

Current conditions

Clear
30°
Clear
Feels like 30°
High 62°·Low 33°
WindCalm
Humidity92%
Dew point28°
Pressure30.53 inHg
Visibility10.0 mi
Cloud cover38%
UV index0 Low
Sunrise7:20 AM
Sunset6:07 PM

Observed at Somerville, Somerset Airport · 59 min ago

Forecast

10-day

  • Saturday

    Areas of frost before 9am. Mostly sunny, with a high near 62. Northeast wind 0 to 5 mph.

  • Saturday Night

    Areas of frost after 11pm. Mostly clear, with a low around 33. West wind around 5 mph.

  • Sunday

    Widespread frost before 9am. Sunny, with a high near 65. West wind around 5 mph.

National Weather Service forecast updated 1 day ago.

Hourly

Hourly forecast
  1. Now Patchy Frost 37°
  2. 9 AM Mostly Sunny 42°
  3. 10 AM Mostly Sunny 50°
  4. 11 AM Mostly Sunny 54°
  5. 12 PM Mostly Sunny 57°
  6. 1 PM Mostly Sunny 60°
  7. 2 PM Mostly Sunny 61°
  8. 3 PM Sunny 61°
  9. 4 PM Sunny 62°
  10. 5 PM Sunny 61°
  11. 6 PM Mostly Clear 57°
  12. 7 PM Mostly Clear 52°
  13. 8 PM Mostly Clear 45°
  14. 9 PM Mostly Clear 43°
  15. 10 PM Mostly Clear 41°
  16. 11 PM Patchy Frost 39°
  17. Sun12 AM Patchy Frost 38°
  18. 1 AM Areas Of Frost 37°
  19. 2 AM Areas Of Frost 36°
  20. 3 AM Areas Of Frost 35°
  21. 4 AM Areas Of Frost 34°
  22. 5 AM Areas Of Frost 34°
  23. 6 AM Widespread Frost 33°
  24. 7 AM Widespread Frost 33°

10-day forecast

Details
  1. FriOct 23 Sunny Sunny34°60°
  2. TodayOct 24 Areas Of Frost then Mostly Sunny Areas Of Frost then Mostly Sunny33°62°
  3. SunOct 25 Widespread Frost then Sunny Widespread Frost then Sunny36°65°
  4. MonOct 26 Sunny Sunny46°69°
  5. TueOct 27 Sunny Sunny40°63°
  6. WedOct 28 Mostly Sunny Mostly Sunny42°60°
  7. ThuOct 29 Mostly Sunny Mostly Sunny45°65°
  8. FriOct 30 Cloudy Cloudy47°65°
  9. SatOct 31 Sunny Sunny39°56°
  10. SunNov 1 Mostly sunny Mostly sunny37°58°

Days after the National Weather Service's seven are MET Norway's outlook, a computer model with no forecaster's review.

Radar

Full map
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Weather news in New Jersey

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Air quality

49
Good
Fine particles (PM2.5)

Air quality is satisfactory, and air pollution poses little or no risk.

Forecast

  • SatModerate (55)
  • SunModerate (65)
  • MonModerate (65)

Central, NJ reporting area · 1 hr ago. Data from AirNow (EPA and its state, local and tribal partners); preliminary and subject to change.

Sun & moon

Sunrise 7:20 AM
Sunset 6:07 PM
Daylight 10 h 47 min (−2 min 29 s tomorrow)
Waxing Gibbous · 96% lit
Moonrise 4:57 PM Moonset 5:32 AM
Full moon Oct 26 New moon Nov 9

Almanac

Monthly
Normal high / low62° / 43°
Month to date2.14 in (normal 2.88 in)

Trenton Area, records since 1865. Normals 1991–2020. Data from NOAA's Regional Climate Centers (ACIS).

Nearby

Forecasters' discussion

From the National Weather Service office in PHI, issued 10 hrs ago

What Has Changed

Aviation section updated for 00Z TAFs.

Marine section updated.

Key Messages

1. Elevated tide cycles persist due to Post- Tropical Cyclone Josephine well off the coast, resulting in widespread minor coastal flooding continuing for back bay areas in Ocean County, NJ and Sussex County, DE.

2. Frost and freeze impacts tonight and Saturday night where the growing season continues.

Discussion

KEY MESSAGE 1...Elevated tide cycles persist due to Post- Tropical Cyclone Josephine well off the coast, resulting in widespread minor coastal flooding continuing for back bay areas in Ocean County, NJ and Sussex County, DE.

Post-Tropical Cyclone Josephine has pulled away from the region as it's now over the Canadian Maritimes. However elevated water levels persist, mainly in the back bay areas of Ocean County, NJ and Sussex County, Delaware. The Coastal Flood Advisory for these counties is in effect until 7 AM Saturday.

KEY MESSAGE 2...Frost and freeze impacts tonight and Saturday night where the growing season continues.

A Freeze Warning was issued for areas north and west of the I-95 corridor from midnight until 9 AM Saturday where the growing season remains active. For the I-95 corridor and areas south and east, a Frost Advisory was issued from midnight until 9 AM Saturday for all other zones, excluding Sussex County in Delaware and the barrier islands in New Jersey.

As an upper-level trough pivots across the Northeast tonight, a strong mid-level ridge in the Plains to Midwest shifts eastward through the weekend. This will support strong surface high pressure shifting eastward into the Northeast and Mid-Atlantic through the weekend.

A chilly and dry airmass will accompany this strong surface high, and as the high itself settles more overhead, forecast soundings show surface winds decoupling. This will set the stage for efficient radiational cooling both tonight and Saturday night. The forecast lows are in the upper 20s to mid 30s for much of the area (with the only exception along the immediate coastal strip) with a favorable setup for frost and freeze. Some scattered to broken cirrus will be in place overnight. However, the thin cloud coverage will be the only limiting reagent to the efficient radiational cooling. This will probably slow cooling down by a few degrees at best, likely aiding to prevent a widespread freeze situation, but it is not expected to slam the brakes hard on the efficient radiational cooling setup overnight.

Aviation

The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY and surrounding areas.

Tonight...VFR. Winds will go calm for a time, then increase slightly out of the north to northeast less than 5 kts after 06Z. High confidence.

Saturday...VFR. Winds 5 kts or less favoring a north to northeast direction early, then shifting more easterly and becoming variable after 18Z. Winds may become calm at times. High confidence.

Saturday night...VFR/SKC. Calm winds. High confidence.

Outlook...

Sunday through Wednesday...VFR. No significant weather expected.

Forecasts, observations and alerts in the United States come from the National Weather Service (NOAA); radar from NOAA's Multi-Radar Multi-Sensor system; satellite imagery from NASA's Global Imagery Browse Services (GIBS) and NOAA's GOES satellites; the map from the U.S. Geological Survey's National Map; air quality from AirNow (EPA and its partners); hurricane information from the National Hurricane Center; climate normals and records from NOAA's Regional Climate Centers (ACIS). Forecasts outside the United States and the UV index: MET Norway (CC BY 4.0); observations outside the U.S.: airport reports via NOAA's Aviation Weather Center. Place names: GeoNames (CC BY 4.0). Data are copied on a schedule and may lag the sources; for warnings that affect your safety, follow your local National Weather Service office and emergency officials. Weather news is drawn from the 4Conservative index and reflects what the press published. Terms of use.