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Iselin, New Jersey Weather

Cicadas claim the afternoon. Day 15 of summer. Read this microseason across nine climate regions →

Iselin weather forecast — hour by hour, 7-day outlook, NOAA radar

Iselin, NJ
Sunday, July 5 at 5:33 AM
73
°
Overcast
Feels like
81°
Humidity
90%
Wind
3 mph
Sunrise
1:32 AM
Sunset
4:31 PM
Iselin, NJ
Hour by hour · 24h
24-Hour ForecastIselin, NJ: 24-hour forecast. Temperatures range from 72 to 83 degrees Fahrenheit with a 64% chance of precipitation at 12 AM.
L 72°H 83°
Iselin, NJ
7-day forecast
  1. Today
    Jul 5
    Rain
    71%
    0.13″
    83°73°—
  2. Monday
    Jul 6
    Rain
    93%
    0.56″
    75°70°-8°
  3. Tuesday
    Jul 7
    Light Drizzle
    87%
    0.02″
    71°64°-4°
  4. Wednesday
    Jul 8
    Overcast
    21%
    —
    75°64°+4°
  5. Thursday
    Jul 9
    Overcast
    17%
    —
    82°66°+7°
  6. Friday
    Jul 10
    Drizzle
    35%
    —
    85°68°+3°
  7. Saturday
    Jul 11
    Overcast
    24%
    —
    81°66°-4°
Iselin, NJ
Next 24 hours · Mild now
68°77°86°6a12p6p12anow 73°high 83°low 72°PRECIP %
Iselin, NJ
Anemometer · 24h winds · from true
NESW
From · True
W
280° · veering 30°
Direction
W
280°
Sustained
3
mph
Gust
11
mph
Peak 24h
33
avg 7
Beaufort · 1 · LIGHT AIR
0
CALM
<1
1
LIGHT AIR
1–3
2
LIGHT BRZ
4–7
3
GENTLE BRZ
8–12
4
MOD BRZ
13–18
5
FRESH BRZ
19–24
6
STRONG BRZ
25–31
7
NEAR GALE
32–38
24h · sust vs gust · mph
avg 7 · pk 33 @ 11:00p
01020MPHB1B2B3B4B5-21h-18h-15h-12h-9h-6h-3h-24hNOWpk 135SUSTGUST
−24h−18h−12h−6hnow
Light breeze veering 30° from the w.
Iselin, NJ
Barometer · 24h pressure · mb
STORMRAINCHANGEFAIRDRY9901000101010201030
Pressure · mb
1010.3
-0.5 mb in 3h · steady · 29.83 inHg
Now
1010.3
mb
3h
-0.5
mb
12h
+1.7
mb
24h
-0.6
mb
Regime · CHANGE
STORM
RAIN
CHANGE
FAIR
DRY
24h · Pressure · mb
range 1008–1013
1000STORM|RAIN10051010RAIN|CHG1015CHG|FAIR10201025FAIR|DRY1030-21h-18h-15h-12h-9h-6h-3h-24hNOW1012.71007.61010.0
−24h−18h−12h−6hnow
Air sits at the threshold — small shifts decide the day.
Iselin, NJ
Air quality
40
AQI
Good
↓-26 in 6h

AQI 40 (Good), driven by PM2.5. AQI down 26 over the last 6 hours — air quality is improving sharply. PM2.5 at 7.9 µg/m³ (AQI 44) with a 0.99 fine-to-coarse ratio and 3 mph wind — combustion smoke trapped in calm air, not road dust.

OK No precautions needed for the general population; unusually sensitive individuals may consider limiting prolonged outdoor exertion.

PM 2.5DRIVERGood
7.9μg/m³
PM 10Good
8μg/m³
NO₂Good
14μg/m³
OzoneGood
59μg/m³
UV IndexLow
0.0

What's driving it

PM × Wind × Precip

PM2.5 at 7.9 µg/m³ (AQI 44) with a 0.99 fine-to-coarse ratio and 3 mph wind — combustion smoke trapped in calm air, not road dust.

PM2.5/PM10
0.99
Wind
calm
Recent rain
0h in last 6h
Pattern
stagnant smoke

Trends

Seven days of AQI and PM2.5.

Hourly air-quality data from the Copernicus Atmosphere Monitoring Service, charted across the past and next several days. Dashed lines mark the AQI breakpoints at 50 (Good → Moderate) and 100 (Moderate → Unhealthy for Sensitive Groups).

7-DAY AQI TREND50100SUNMONTUEWEDTHUFRISATSUN7-DAY PM2.5 TREND · μg/m³770
Iselin, NJ
Sky cover · visibility · 24h
Cloud cover
92%
OVERCAST
100%0%−24h−18h−12h−6hnow
Visibility
28.9mi
UNLIMITED
111 mi0 mi−24h−18h−12h−6hnow
Earth · GOES-19 ABI
Full Disk · Visible · GeoColor
GOES-19 full disk Visible · GeoColor
True-color daytime, blue/IR sandwich at night
09:33 UTC · Iselin, NJ · NOAA NESDIS / STAR · up to 10848 px
Continental US · GOES-19 ABI
CONUS Sector · Visible · GeoColor
GOES-19 CONUS Visible · GeoColor
Daytime true-color, blue-light/IR sandwich at night
09:33 UTC · Iselin, NJ · NOAA NESDIS / STAR · 5-min cadence · up to 10000 px
Iselin, NJ
Satellite · infrared · animated
Iselin, NJ
Loading IR frames…
IR · cloud-top temp© RainViewer · Carto
Iselin, NJ
Almanac · Sunday, July 5
If the first of July be rainy weather, 'twill rain more or less for four weeks together.
Civil dawn
5:00 AM
Sunrise
1:32 AM
Daylight
14h 59m
Sunset
4:31 PM
Civil dusk
9:05 PM
Planting note
Harvest early potatoes. Begin drying onions on the surface.
Iselin, NJ
The moon
Waning Gibbous
74% illuminated
Moonrise
11:14 PM
Moonset
11:06 AM
In sign
♓︎ Pisces
Iselin, NJ
Microseason
Jul 1–5

Cicadas claim the afternoon

fish
Jan 151% of the yearDec 31

Read this microseason across nine climate regions →

Iselin at a glance

  • Today vs. normal: 73°F — typical for the season
  • Last frost: April 19 (climatological average for this latitude)
  • Microseason: Jul 1–5
  • Planting window: Harvest early potatoes. Begin drying onions on the surface.

ZIP code: 08830

15-Day Forecast — Iselin

  1. Sun83°73°71%
  2. Mon75°70°93%
  3. Tue71°64°87%
  4. Wed75°64°21%
  5. Thu82°66°17%
  6. Fri85°68°35%
  7. Sat81°66°24%
  8. Sun80°65°23%
  9. Mon73°63°19%
  10. Tue82°62°13%
  11. Wed82°67°15%
  12. Thu90°68°33%
  13. Fri83°70°27%
  14. Sat83°69°33%
  15. Sun88°69°32%

Forecast data from Open-Meteo (CC BY 4.0).

Right now in the garden

Peak growing season

As of July 5, the growing season is at its peak — frost is months away. Continue succession-planting beans and summer squash. Start fall brassicas (broccoli, cabbage, kale) from seed indoors for transplanting in late summer.

SPC Convective Outlook

Storm Prediction Center — Iselin

SPC has placed Iselin in the Slight Risk category for severe thunderstorms today.

  • TODAYSLGTSlight Risk
  • TOMORROWTSTMGeneral Thunderstorms
  • DAY 3NONENo severe risk

Scattered severe storms possible. A few tornadoes, hail, and damaging wind gusts possible.

Source: NOAA / NWS Storm Prediction Center categorical convective outlook. Outlooks are re-issued multiple times per day; this page reflects the most recent SPC polygons covering the city’s coordinates.

January 1–5: The year turns in silence.January 6–10: Ice thickens on still water.January 11–15: Shortest shadows lengthen.January 16–20: Pheasants begin to call.January 21–25: Springs begin to thaw.January 26–31: Chickadees announce dawn.February 1–5: East wind softens the frost.February 6–10: Sap begins to rise.February 11–15: First snowdrops appear.February 16–20: Red-winged blackbirds return.February 21–25: Rain begins to replace snow.February 26–28: Skunk cabbage pushes through ice.March 1–5: Ice withdraws from the reservoir.March 6–10: Crocuses open to weak sun.March 11–15: Peepers call from the marsh.March 16–20: Woodcocks spiral at dusk.March 21–25: Equinox — light overtakes dark.March 26–31: Forsythia opens along the fences.April 1–5: Cherry blossoms drift like snow.April 6–10: Warblers appear in the understory.April 11–15: Magnolias bloom and fall in a day.April 16–20: Dogwoods float above the forest.April 21–25: Lilacs perfume the evening.April 26–30: Last frost releases the garden.May 1–5: Warblers flood the Ramble.May 6–10: Tulip poplars light their candles.May 11–15: Shad run up the rivers.May 16–20: Roses open along the stoops.May 21–25: Firefly scouts appear at dusk.May 26–31: Strawberries ripen in the sun.June 1–5: Fireflies rise from the lawn.June 6–10: Elderflowers open in hedgerows.June 11–15: Solstice approaches — longest light.June 16–20: Honeysuckle sweetens the night.June 21–25: Solstice — the sun stands still.June 26–30: Lightning bugs drift through oaks.July 1–5: Cicadas claim the afternoon.July 6–10: Queen Anne's lace lines the roads.July 11–15: Thunder builds each afternoon.July 16–20: Corn reaches for the tassels.July 21–25: Dog days settle in the haze.July 26–31: Katydids begin their chorus.August 1–5: Night falls a minute earlier.August 6–10: Sunflowers face the morning.August 11–15: Goldenrod begins to bloom.August 16–20: Crickets pulse through warm nights.August 21–25: First cool morning surprises.August 26–31: Monarchs stage for flight.September 1–5: School buses reappear.September 6–10: Asters purple the roadsides.September 11–15: Hawk migration over the Hudson.September 16–20: Equinox — dark overtakes light.September 21–25: Apples hang heavy on the branch.September 26–30: Geese begin to chevron south.October 1–5: Witch hazel blooms as others fade.October 6–10: Maples begin to blaze.October 11–15: Frost paints the garden black.October 16–20: Oaks turn bronze and russet.October 21–25: Leaves rattle down the gutters.October 26–31: Clocks fall back — dusk at five.November 1–5: Ginkgos drop overnight.November 6–10: Last leaves cling stubbornly.November 11–15: Juncos arrive from the north.November 16–20: Bare branches reveal the sky.November 21–25: First flurries dust the rooftops.November 26–30: Woodsmoke curls through the block.December 1–5: Darkness settles before dinner.December 6–10: Holly and winterberry persist.December 11–15: Shortest day approaches.December 16–20: Ice begins to form at the edges.December 21–25: Solstice — the sun begins return.December 26–31: The year turns in silence.🌱February 14 — First skunk-cabbage spathes thaw their way up☀️March 20 — Spring equinox — day and night balance🌸April 5 — Cherry blossoms peak in the parks🐦May 10 — Warbler migration peaks along the coast✨May 25 — First fireflies scout the meadows at dusk🌞June 21 — Summer solstice — longest day🦗July 25 — Peak cicada chorus in the afternoons🌊August 18 — Warmest sea-surface temperatures of the year🍂September 22 — Autumn equinox — the slow turn❄️October 25 — First widespread frost in the suburbs🍁November 10 — Peak leaf color across the Hudson Valley🌙December 21 — Winter solstice — longest night

Microseason · July 1–5

Cicadas claim the afternoon

Annual cicada buzz begins, peaking in the heat of the day.

Day 186 of 365 · Wedge 37 of 72

The solar year drawn as a wheel of 72 five-day windows. Each wedge is one microseason; the four colored arcs mark winter, spring, summer, and autumn; the small icons sit at notable phenological events. The crimson pointer creeps clockwise as the year turns.

Planting calendar

MonthPlantHarvest
January——
February——
March——
Aprillettuce, peas, spinach, radishes—
Maylettuce, peas, spinach, radishes, tomatoes, peppers, beans, squashlettuce, peas, radishes
Junetomatoes, peppers, beans, squashlettuce, peas, radishes
Julytomatoes, peppers, beans, squashtomatoes, beans, summer squash
August—tomatoes, beans, summer squash
Septemberfall brassicas, garlic (overwinter), carrotstomatoes, beans, summer squash
Octoberfall brassicas, garlic (overwinter), carrotswinter squash, tomatoes (last)
November——
December——

A year in weather

Iselin peaks at about 77°F in July and bottoms near 30°F in January; December brings the heaviest rain (4.2 inches) and February the least (3.0 inches).

MonthMean tempPrecipRainy days
January30°3.4″14
February32°3.0″13
March41°3.7″15
April52°3.9″17
May61°3.7″18
June70°3.8″17
July77°3.5″16
August75°4.0″17
September69°3.6″13
October58°3.1″11
November44°3.7″13
December35°4.2″13

Regional context

Per NOAA NCEI 1991-2020 normals, Iselin runs from a 30°F January mean to 77°F in July, a 46°F seasonal spread, with near 43.6 inches of precipitation across about 175 wet days.

Rainfall in Iselin stays even across the calendar: December tops out at 4.2 inches over 13.3 rainy days, and February still logs 3.0 inches across 12.5 — a narrow range for Iselin. That lines Iselin up with places like Menlo Park Terrace, NJ, Colonia, NJ and Fords, NJ, fed by overlapping storm tracks.

Around mid-April, Iselin sheds its freezing nights — peas, lettuce, spinach, and radishes go into Iselin's beds. Heat-demanding starts go out a fortnight on in Iselin, after the soil warms and cold snaps clear. The season ends by mid-November in Iselin, once hard frosts set back in. Iselin's low ground holds frost later into spring than Iselin's benches, which run 3-5 days ahead.

Similar climates: Menlo Park Terrace, NJ, Colonia, NJ, Fords, NJ, Avenel, NJ, Metuchen, NJ.

Frequently asked

When does it freeze in Iselin?
Frost typically leaves Iselin by mid-April and returns to Iselin near mid-November.
What is the rainy season in Iselin?
Iselin sees its heaviest rain in December (around 4.2 inches), part of roughly 44 inches a year.
What is the warmest month in Iselin?
The warmest stretch in Iselin comes in July, around 77°F on average.
What is the coldest month in Iselin?
On average January is the chilliest month in Iselin, about 30°F.
When can I start a vegetable garden in Iselin?
Frost-hardy sowings begin at mid-April in Iselin; warm-season starts follow two weeks on.
How many rainy days does Iselin get?
Iselin records around 175 days of measurable precipitation annually.
What hardiness zone is Iselin?
Iselin's USDA zone comes from its January mean (30°F); enter the ZIP on the USDA lookup for the number.
What is the 10-day forecast for Iselin?
Iselin's extended outlook — daily high and low temperatures and precipitation chances for each upcoming day — is in the daily forecast above.
Will it rain this week in Iselin?
See this week's day-by-day rain chances for Iselin in the daily forecast above, and the next 24 hours in the hourly chart.
What is the weather like right now in Iselin?
Current conditions for Iselin and the next 24 hours — temperature, precipitation chance, and wind by the hour — are in the hourly forecast chart above.
How often is the Iselin forecast updated?
The Iselin forecast on this page is built from Open-Meteo weather-model data and refreshes regularly through the day.
When are sunrise and sunset in Iselin?
Today's sunrise and sunset times for Iselin are in the Almanac section above, along with civil dawn, civil dusk, and day length. Day length is longest near the summer solstice and shortest near the winter solstice.
How accurate is the weather forecast for Iselin?
The next few days in Iselin's forecast are the most reliable; accuracy declines beyond about a week as weather-model uncertainty grows.

Climate

Iselin, New Jersey occupies a warm-summer humid continental zone, with January means near 30°F and July around 77°F — a 47°F swing.

Across the year, Iselin collects about 44 inches of precipitation over roughly 175 days with measurable rain or snow.

Latitude 40.6°N gives Iselin its 47°F swing, and with it the rhythm of Iselin's growing season.

Beaches near Iselin

Each linked page shows live water temperature, wave height, swim and surf verdicts, tides, and rip-current risk from NDBC + NOAA + NWS data.

All cities in New Jersey →

Staten Island, NY weather →

ZIP codes in Iselin

  • 08830

Climate normals from the Open-Meteo Climate API. Köppen approximation from NOAA NCEI U.S. Climate Regions. See methodology for data sources, editorial rules, and corrections. Maintainer: Brian Tighe.