Wilmington weather in December

In December, Wilmington sees average daytime highs of 45°F and overnight lows near 33°F, with 3.9 in of precipitation across 9 wet days and about 9.2 hours of daylight. It is the 10th-warmest and 4th-wettest month of the year here.

Highs ease over the month, from about 49°F in the first days to 43°F by the end. The sky is clear or mostly clear about 33% of the time in December, and the air most often feels dry.

Daylight stretches from about 9 h 24 min at the start of December to 9 h 12 min by month's end. Set against the rest of the year, December is Wilmington's 7th-clearest and 5th-windiest month. For the whole year in context, see Wilmington's year-round climate.

Daytime high
45°
10th warmest
Overnight low
33°
3rd coldest
Precipitation
3.9 in
9 wet days
Daylight
9 h 12 min
7:22 AM – 4:34 PM
Cloud cover
60%
7th clearest
Wind
8 mph
5th windiest
Solar energy
1.85 kWh/m²
Travel score
1.1
out of 10

Wilmington is seat of New Castle County, and largest city in Delaware, United States.

Density
1,615/km²
people per km²
Founded
1638

Air quality: WHO Ambient Air Quality Database. Density & description: Wikidata (CC0), GeoNames.

Temperature in December

Average highAverage lowShaded bands: 10–90% of days

Highs ease over the month, from about 49°F in the first days to 43°F by the end.

A typical December day in Wilmington reaches about 45°F in the afternoon and slips back to 33°F overnight — a 13°F spread between the day's warmth and the night's chill. On most days the high lands between 33°F and 58°F. Set against its neighbours, December runs about 9°F cooler than November and about 5°F warmer than January.

20°40°60°151015202531
Avg high (°F)Avg low (°F)
15036
24936
34935
44835
54835
64735
74734
84734
94634
104633
114633
124633
134533
144533
154532
164532
174532
184432
194432
204432
214431
224431
234431
244431
254431
264331
274331
284330
294330
304330
314330

How December really feels in Wilmington

Once humidity and wind are folded in, December averages 0 days that feel above 90°F and 31 that feel at or below 32°F — the comfort signal a plain temperature reading hides.

Days feeling ≥ 90°F
0
heat index over the day's high
Days feeling ≤ 32°F
31
wind chill below the day's low

The story in December is cold — wind chill drags the overnight "feels like" below the raw low.

Wilmington weather by month

How December compares with the rest of the year at a glance. December is the 10th-warmest and 4th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°F)Rainfall (inches)Wet daysSnow daysDaylight (hours)Travel score
Jan41° / 28°3.29.23.69.50.1
Feb43° / 29°3.08.73.210.40.6
Mar52° / 36°4.110.72.111.72.7
Apr63° / 46°3.610.50.3135.4
May73° / 55°3.510.9014.26.5
Jun81° / 65°3.910.4014.86.0
Jul86° / 70°3.910.9014.55.0
Aug83° / 68°3.910.4013.65.6
Sep77° / 61°4.29.6012.36.9
Oct66° / 50°3.68.1010.96.3
Nov55° / 40°3.07.90.29.83.6
Dec45° / 33°3.991.99.21.1

Cloud cover in December

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 33% of the time in December.

Beyond those clear spells, partly cloudy skies cover about 14% of December, with mostly cloudy or overcast conditions the remaining 53%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
14753
24753
34753
44654
54654
64654
74555
84555
94555
104555
114555
124555
134555
144555
154654
164654
174654
184753
194753
204951
214951
225050
235149
245149
255149
265149
275149
285050
295050
304951
315050

Chance of precipitation in December

Any precipitationSnow

Wilmington gets around 3.9 in of rain and snow over 9 wet days in December. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable precipitation averages around 29% and peaks near 31% on the wettest days, and about 2 days bring snow.

0%10%20%30%40%151015202531
Rain chance (%)Snow chance (%)
1293
2303
3304
4304
5304
6315
7315
8315
9316
10316
11316
12316
13316
14316
15316
16316
17306
18307
19307
20297
21297
22287
23287
24276
25276
26276
27276
28277
29287
30287
31288

Humidity in December

DryComfortableHumidMuggyOppressiveMiserable

Most of December feels dry — the stacked bands show each day's mix of comfort levels, read off the dew point.

By dew point, December lands in the dry band about 99% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)
1973
2973
3973
4982
5982
6982
7982
8982
9991
10991
11991
12991
13991
14991
15991
16991
17991
18991
19991
20991
21991
22991
23991
24991
25991
26991
27991
28991
291000
301000
311000

Wind in December

Winds average 8 mph in December.

Across December, daily wind ranges from about 7 mph on the calmest days to 8 mph at its breeziest. It stays fairly steady from day to day.

0246810151015202531
Wind speed (mph)Feels
17light breeze
27light breeze
37light breeze
47light breeze
57light breeze
67light breeze
77light breeze
87light breeze
97light breeze
107light breeze
117light breeze
127light breeze
138light breeze
148light breeze
158light breeze
168light breeze
178light breeze
188light breeze
198light breeze
208light breeze
218light breeze
228light breeze
238light breeze
248light breeze
258light breeze
268light breeze
278light breeze
288light breeze
298light breeze
308light breeze
318light breeze

Sunrise & sunset in December

DaylightNight

Daylight runs from about 9 h 24 min at the start of December to 9 h 12 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 12 minutes over December. Sunrise moves from 7:10 AM to 7:29 AM, and sunset from 4:34 PM to 4:42 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
19.47:104:34
29.47:114:34
39.47:124:33
49.37:134:33
59.37:144:33
69.37:154:33
79.37:164:33
89.37:164:33
99.37:174:33
109.37:184:33
119.27:194:33
129.27:204:33
139.27:204:34
149.27:214:34
159.27:224:34
169.27:224:34
179.27:234:35
189.27:244:35
199.27:244:35
209.27:254:36
219.27:254:36
229.27:264:37
239.27:264:37
249.27:274:38
259.27:274:38
269.27:274:39
279.27:284:39
289.27:284:40
299.27:284:41
309.27:284:41
319.27:294:42

Solar energy in December

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in December, about 1.85 kWh/m² — the year's lowest.

For context, solar energy here swings from a low near 1.85 kWh/m² to a high of 6.11 kWh/m² in June across the year — December's 1.85 kWh/m² sits near the bottom.

00.511.522.5151015202531
Solar energy (kWh/m²)Level
12.0Dim
22.0Dim
31.9Dim
41.9Dim
51.9Dim
61.9Dim
71.9Dim
81.9Dim
91.9Dim
101.8Dim
111.8Dim
121.8Dim
131.8Dim
141.8Dim
151.8Dim
161.8Dim
171.8Dim
181.8Dim
191.8Dim
201.8Dim
211.8Dim
221.9Dim
231.9Dim
241.9Dim
251.9Dim
261.9Dim
271.9Dim
281.9Dim
291.9Dim
301.9Dim
311.9Dim
Planning a trip in December

Hazard calendar for Wilmington

In seasonPeak

None of Wilmington's seasonal hazards are active in December. The full-year calendar below shows when the rainy season, cyclone risk and dust haze do peak.

Wilmington sits in the Atlantic hurricane belt; the season peaks August–October.

Atlantic hurricane
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec

Is December a good time to visit Wilmington?

Our two travel scores rate December for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal).

1.1
Sightseeing
10th-best month of the year
0.0
Beach & pool
10th-best month of the year

December is a weaker month for outdoor sightseeing in Wilmington.

What to pack for Wilmington in December

From December's temperature range, rain chance, sun and wind — what's worth putting in the bag.

In December, Wilmington sees daytime highs around 45°F and nights near 33°F. Pack a warm layer. Worth having: a heavy coat and rain gear. About 9 days see rain.

a warm layera heavy coatrain gear

UV index in Wilmington in December

LowModerateHighVery highExtreme

Clear-sky midday UV in December peaks around 2. The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Wilmington peaks around July 11 at about 8 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near December 20 at about 2 (low).

The index reaches 3 or more — the level where the WHO recommends sun protection — in 8 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecModerateHighVery highHighModerateLowJul 11UV 8Dec 20UV 2
UV index (midday)Level
Jan2Low
Feb3Moderate
Mar5Moderate
Apr6High
May8Very high
Jun8Very high
Jul9Very high
Aug6High
Sep6High
Oct4Moderate
Nov3Moderate
Dec2Low

Air quality in Wilmington in December

GoodModeratePoorUnhealthyVery unhealthy

Average fine-particle pollution (PM2.5) through the year — so you can see where December falls, not just the annual average.

Air quality in Wilmington is worst in July — around 17 µg/m³ PM2.5 (moderate), about 2.0× the cleanest month (November, 8 µg/m³).

Modeled monthly averages (CAMS reanalysis, 2015–2024).

01020JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodJul 1317 µg/m³Nov 128 µg/m³
PM2.5 (µg/m³)Level
Jan10Good
Feb12Good
Mar13Moderate
Apr13Moderate
May15Moderate
Jun16Moderate
Jul17Moderate
Aug14Moderate
Sep12Good
Oct9Good
Nov8Good
Dec9Good
Location & terrain

Where is Wilmington?

Wilmington sits at 39.7°N, 75.5°W, 92 ft above sea level, in United States. The nearest listed city is Bear, 9.9 mi away.

Topography around Wilmington

How much the land rises and falls, and what covers it, within 2, 10 and 50 miles of Wilmington.

Within 2 miles, the terrain around Wilmington has only modest variations in elevation — a maximum elevation change of 364 ft around an average of 82 ft above sea level; within 10 miles, only modest variations in elevation — a maximum elevation change of 545 ft; within 50 miles, significant variations in elevation — a maximum elevation change of 1,483 ft.

The land around Wilmington is covered by artificial surfaces (47%) and trees (32%) within 2 miles, trees (51%) within 10 miles, and trees (53%) within 50 miles.

2 miles
364 ft
10 miles
545 ft
50 miles
1,483 ft
treesgrasslandcroplandartificial surfacesbare terrainwaterwetland
December weather nearby: Bear 9.9 mi · Newark 12 mi · Chester 12 mi · West Chester 15 mi · Springfield 17 mi · Elkton 18 mi · Drexel Hill 19 mi · Havertown 21 mi

United States travel facts

Power plugs
Type A / B
120 V · 60 Hz
Prices
≈ 100% of US
price level, 2025
GDP per capita
$90,027
2025
Happiness
6.8 / 10
World Happiness, 2025
Safe drinking water
98%
of population, 2024
Homicide rate
5.8
per 100k, 2023
Road deaths
12.7
per 100k/yr, 2019
Income group
High
World Bank
Religion
Protestant 47%unaffiliated 23%Roman Catholic 21%Jewish 2%

Sources: World Bank, US State Department, World Happiness Report, WHO/UNICEF, EF EPI, CIA World Factbook.

Data sources

Temperature, precipitation, cloud, humidity, wind and solar figures are a 1991–2020 climatology for Wilmington (39.746°, -75.5466°, elevation 92 ft), computed from hourly ERA5 reanalysis — contains modified Copernicus Climate Change Service information. Sun figures are astronomical calculations, not observations. City data © GeoNames, CC BY 4.0. Map outlines from Natural Earth (public domain); interactive map © Google. Tropical-cyclone seasons are the published climatological basin seasons (NOAA National Hurricane Center / regional warning centres). UV index is derived from CAMS (Copernicus Atmosphere Monitoring Service) clear-sky UV data — contains modified Copernicus Atmosphere Monitoring Service information. Monthly air-quality (PM2.5) seasonality is from the CAMS EAC4 reanalysis (Copernicus Atmosphere Monitoring Service), scaled to the WHO annual mean where available. Topography is sampled from the Copernicus DEM GLO-90 elevation model (© ESA/Airbus) and ESA WorldCover 2021 land cover (CC BY 4.0).