Weather StoryAlmanac, microseasons, and the day's weather story.

New Castle, Delaware Weather

Cicadas claim the afternoon. Day 14 of summer. Read this microseason across nine climate regions →

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

New Castle, DE
Saturday, July 4 at 3:31 PM
101
°
Clear
Feels like
105°
Humidity
30%
Wind
8 mph
Sunrise
1:39 AM
Sunset
4:33 PM
New Castle, DE
Hour by hour · 24h
24-Hour ForecastNew Castle, DE: 24-hour forecast. Temperatures range from 76 to 101 degrees Fahrenheit with a 22% chance of precipitation at 2 AM.
L 76°H 101°
New Castle, DE
7-day forecast
  1. Today
    Jul 4
    Partly Cloudy
    21%
    —
    101°79°—
  2. Sunday
    Jul 5
    Light Rain
    40%
    0.11″
    94°75°-7°
  3. Monday
    Jul 6
    Thunderstorm
    90%
    0.59″
    76°72°-18°
  4. Tuesday
    Jul 7
    Light Showers
    75%
    —
    83°68°+7°
  5. Wednesday
    Jul 8
    Light Drizzle
    18%
    0.01″
    80°66°-3°
  6. Thursday
    Jul 9
    Overcast
    15%
    —
    91°67°+11°
  7. Friday
    Jul 10
    Light Drizzle
    36%
    —
    91°71°0°
New Castle, DE
Next 24 hours · Hot now
HOT 90°70°90°110°12p6p12a6anow 100°high 101°low 76°PRECIP %
New Castle, DE
Anemometer · 24h winds · from true
NESW
From · True
WSW
247° · veering 12°
Direction
WSW
247°
Sustained
8
mph
Gust
16
mph
Peak 24h
17
avg 5
Beaufort · 3 · GENTLE BRZ
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 5 · pk 17 @ 7:00p
0102030MPHB1B2B3B4B5B6-21h-18h-15h-12h-9h-6h-3h-24hNOWpk 265SUSTGUST
−24h−18h−12h−6hnow
Light breeze veering 12° from the wsw.
New Castle, DE
Barometer · 24h pressure · mb
STORMRAINCHANGEFAIRDRY9901000101010201030
Pressure · mb
1012.3
-2.1 mb in 3h · falling rapidly · 29.89 inHg
Now
1012.3
mb
3h
-2.1
mb
12h
-1.7
mb
24h
-2.4
mb
Regime · CHANGE
STORM
RAIN
CHANGE
FAIR
DRY
24h · Pressure · mb
range 1012–1015
9951000STORM|RAIN10051010RAIN|CHG1015CHG|FAIR10201025FAIR|DRY1030-21h-18h-15h-12h-9h-6h-3h-24hNOW1015.21012.51012.5
−24h−18h−12h−6hnow
Pressure slipping through the change line — wetter air on the way.
New Castle, DE
Air quality
78
AQI
Moderate
↑+24 in 6h▲Peak ~113 @ 11 PM

AQI 78 (Moderate), driven by Ozone. AQI up 24 in the last 6 hours — air quality is degrading. Ozone at AQI 108 — peak already passed at 1 PM under clear skies. Levels should ease through evening.

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

PM 2.5Good
7.0μg/m³
PM 10Good
8μg/m³
NO₂Good
1μg/m³
OzoneDRIVERUnhealthy
143μg/m³
UV IndexHigh
6.6

What's driving it

Ozone × UV × Sky

Ozone at AQI 108 — peak already passed at 1 PM under clear skies. Levels should ease through evening.

Present
AQI 108
UV peak
6.3 at earlier today
Sky at peak
clear
Projected peak
AQI 108

PM × Wind × Precip

PM2.5 at 7.0 µg/m³, PM10 at 7.5 µg/m³ — typical background levels with no transport signature.

PM2.5/PM10
0.93
Wind
light
Recent rain
0h in last 6h
Pattern
background

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 TREND50100SATSUNMONTUEWEDTHUFRISAT7-DAY PM2.5 TREND · μg/m³320
New Castle, DE
Sky cover · visibility · 24h
Cloud cover
0%
CLEAR
100%0%−24h−18h−12h−6hnow
Visibility
114.6mi
UNLIMITED
113 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
19:31 UTC · New Castle, DE · 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
19:31 UTC · New Castle, DE · NOAA NESDIS / STAR · 5-min cadence · up to 10000 px
New Castle, DE
Satellite · infrared · animated
New Castle, DE
Loading IR frames…
IR · cloud-top temp© RainViewer · Carto
New Castle, DE
Almanac · Saturday, July 4
If the first of July be rainy weather, 'twill rain more or less for four weeks together.
Civil dawn
5:08 AM
Sunrise
1:39 AM
Daylight
14h 54m
Sunset
4:33 PM
Civil dusk
9:07 PM
Planting note
Harvest early potatoes. Begin drying onions on the surface.
New Castle, DE
The moon
Waning Gibbous
79% illuminated
Moonrise
10:55 PM
Moonset
10:06 AM
In sign
♓︎ Pisces
New Castle, DE
Microseason
Jul 1–5

Cicadas claim the afternoon

plant
Jan 151% of the yearDec 31

Read this microseason across nine climate regions →

New Castle at a glance

  • Today vs. normal: 29°F above the seasonal normal for this latitude
  • Last frost: April 14 (climatological average for this latitude)
  • Microseason: Jul 1–5
  • Planting window: Harvest early potatoes. Begin drying onions on the surface.

ZIP code: 19720

16-Day Forecast — New Castle

  1. Sat101°79°21%
  2. Sun94°75°40%
  3. Mon76°72°90%
  4. Tue83°68°75%
  5. Wed80°66°18%
  6. Thu91°67°15%
  7. Fri91°71°36%
  8. Sat89°71°36%
  9. Sun85°69°28%
  10. Mon82°68°22%
  11. Tue88°67°22%
  12. Wed91°66°45%
  13. Thu91°71°41%
  14. Fri94°73°34%
  15. Sat95°71°34%
  16. Sun91°73°45%

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

Right now in the garden

Peak growing season

As of July 4, 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 — New Castle

SPC has placed New Castle in the Enhanced Risk category for severe thunderstorms today.

  • TODAYENHEnhanced Risk
  • TOMORROWSLGTSlight Risk
  • DAY 3TSTMGeneral Thunderstorms

Numerous severe storms likely. Tornadoes, large hail, and damaging wind gusts possible across the area. Track NWS warnings if storms develop.

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.

All cities in Delaware →

Wilmington, DE weather →

ZIP codes in New Castle

  • 19720
  • 19721

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.