Wilton weather in December

In December, Wilton sees average daytime highs of 42°F and overnight lows near 30°F, with 4.2 in of precipitation across 10.1 wet days and about 9.1 hours of daylight. It is the 10th-warmest and 2nd-wettest month of the year here.

Highs ease over the month, from about 45°F in the first days to 39°F by the end. The sky is clear or mostly clear about 30% of the time in December, and the air most often feels dry.

Daylight stretches from about 9 h 12 min at the start of December to 9 h 06 min by month's end. Set against the rest of the year, December is Wilton's 8th-clearest and 3rd-windiest month. For the whole year in context, see Wilton's year-round climate.

Daytime high
42°
10th warmest
Overnight low
30°
3rd coldest
Precipitation
4.2 in
10.1 wet days
Daylight
9 hours
7:19 AM – 4:21 PM
Cloud cover
61%
8th clearest
Wind
8 mph
3rd windiest
Solar energy
1.7 kWh/m²
Travel score
0.3
out of 10

Wilton is town in Fairfield County, Connecticut, United States.

Founded
1802

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 45°F in the first days to 39°F by the end.

A typical December day in Wilton reaches about 42°F in the afternoon and slips back to 30°F overnight — a 11°F spread between the day's warmth and the night's chill. On most days the high lands between 30°F and 54°F. Set against its neighbours, December runs about 10°F cooler than November and about 5°F warmer than January.

20°30°40°50°60°151015202531
Avg high (°F)Avg low (°F)
14634
24634
34533
44533
54433
64433
74432
84332
94331
104231
114231
124231
134231
144130
154130
164130
174130
184130
194129
204029
214029
224029
234029
244029
254028
264028
273928
283928
293928
303927
313927

How December really feels in Wilton

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.

Wilton weather by month

How December compares with the rest of the year at a glance. December is the 10th-warmest and 2nd-wettest month here — the current month is highlighted below.

MonthHigh / Low (°F)Rainfall (inches)Wet daysSnow daysDaylight (hours)Travel score
Jan37° / 24°3.49.35.39.40.0
Feb39° / 25°3.18.84.410.30.0
Mar47° / 32°4.210.53.711.71.4
Apr58° / 42°3.810.80.613.14.2
May68° / 52°3.511.3014.36.0
Jun78° / 62°3.911.1014.96.5
Jul83° / 67°3.710.9014.75.7
Aug81° / 66°4.110.4013.66.4
Sep74° / 59°3.99.4012.36.9
Oct62° / 48°4.18.80.110.95.5
Nov51° / 38°3.38.50.79.72.7
Dec42° / 30°4.210.13.59.10.3

Cloud cover in December

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 30% of the time in December.

Beyond those clear spells, partly cloudy skies cover about 15% of December, with mostly cloudy or overcast conditions the remaining 55%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
14753
24753
34753
44654
54654
64555
74456
84456
94357
104357
114258
124258
134258
144258
154258
164258
174258
184357
194456
204555
214555
224753
234753
244852
254852
264951
274951
284951
294951
304951
314852

Chance of precipitation in December

Any precipitationSnow

Wilton gets around 4.2 in of rain and snow over 10.1 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 32% and peaks near 35% on the wettest days, and about 4 days bring snow.

0%10%20%30%40%50%151015202531
Rain chance (%)Snow chance (%)
1327
2328
3338
4339
53410
63410
73411
83511
93512
103512
113412
123412
133412
143312
153312
163212
173211
183111
193111
203011
213010
223010
233011
242911
253011
263011
273012
283112
293113
303113
313214

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 100% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)
1991
2991
3991
4991
51000
61000
71000
81000
91000
101000
111000
121000
131000
141000
151000
161000
171000
181000
191000
201000
211000
221000
231000
241000
251000
261000
271000
281000
291000
301000
311000

Wind in December

Winds average 8 mph in December.

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

051015151015202531
Wind speed (mph)Feels
18light breeze
28light breeze
38light breeze
48light breeze
58light breeze
68light breeze
78light breeze
88light breeze
98light breeze
108light breeze
118light breeze
128light 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 12 min at the start of December to 9 h 06 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 6 minutes over December. Sunrise moves from 7:06 AM to 7:25 AM, and sunset from 4:21 PM to 4:29 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
19.27:064:21
29.27:074:21
39.27:084:21
49.27:094:20
59.27:104:20
69.27:114:20
79.17:124:20
89.17:134:20
99.17:134:20
109.17:144:20
119.17:154:20
129.17:164:20
139.17:164:21
149.17:174:21
159.17:184:21
169.07:194:21
179.07:194:22
189.07:204:22
199.07:204:22
209.07:214:23
219.07:214:23
229.07:224:24
239.07:224:24
249.07:234:25
259.07:234:25
269.07:244:26
279.07:244:26
289.07:244:27
299.17:244:28
309.17:254:28
319.17:254:29

Solar energy in December

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in December, about 1.7 kWh/m² — the year's lowest.

For context, solar energy here swings from a low near 1.7 kWh/m² to a high of 6.05 kWh/m² in June across the year — December's 1.7 kWh/m² sits near the bottom.

00.511.522.5151015202531
Solar energy (kWh/m²)Level
11.8Dim
21.8Dim
31.8Dim
41.8Dim
51.8Dim
61.8Dim
71.7Dim
81.7Dim
91.7Dim
101.7Dim
111.7Dim
121.7Dim
131.7Dim
141.7Dim
151.7Dim
161.7Dim
171.7Dim
181.7Dim
191.7Dim
201.7Dim
211.7Dim
221.7Dim
231.7Dim
241.7Dim
251.7Dim
261.7Dim
271.7Dim
281.7Dim
291.7Dim
301.8Dim
311.8Dim
Planning a trip in December

Hazard calendar for Wilton

In seasonPeak

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

Wilton 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 Wilton?

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

0.3
Sightseeing
10th-best month of the year
0.0
Beach & pool
9th-best month of the year

December is a weaker month for outdoor sightseeing in Wilton.

What to pack for Wilton in December

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

In December, Wilton sees daytime highs around 42°F and nights near 30°F. Pack a warm layer. Worth having: a heavy coat and rain gear. About 10 days see rain.

a warm layera heavy coatrain gear

Sea temperature near Wilton in December

The nearest coast averages about 46°F in December — the other half of the beach question. The full-year curve and swim-comfort zones are below.

The sea offshore is warmest in August at about 74°F and coldest in February near 35°F.

It's comfortable for a long swim from Jun 30 to Sep 30 — about 3.1 months when the water holds above 68°F.

30°40°50°60°70°80°JanFebMarAprMayJunJulAugSepOctNovDecbracingcoolrefreshingwarmtropicalcomfortable to swim
Sea temperature (°F)Comfort
Jan39Bracing
Feb35Bracing
Mar37Bracing
Apr44Bracing
May55Bracing
Jun65Cool
Jul72Refreshing
Aug74Refreshing
Sep71Refreshing
Oct64Cool
Nov55Bracing
Dec46Bracing

UV index in Wilton in December

LowModerateHighVery highExtreme

Clear-sky midday UV in December peaks around 1. The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Wilton peaks around July 11 at about 8 (very high) — sunscreen and a hat are worth it in the middle of the day. It bottoms out near December 23 at about 1 (low).

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

025710JanFebMarAprMayJunJulAugSepOctNovDecLowModerateHighVery highHighModerateLowJul 11UV 8Dec 23UV 1
UV index (midday)Level
Jan2Low
Feb3Moderate
Mar5Moderate
Apr6High
May7Very high
Jun8Very high
Jul8Very high
Aug6High
Sep6High
Oct3Moderate
Nov2Moderate
Dec1Low

Air quality in Wilton 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 Wilton is worst in July — around 20 µg/m³ PM2.5 (moderate), about 1.7× the cleanest month (November, 11 µg/m³).

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

0102030JanFebMarAprMayJunJulAugSepOctNovDecModerateGoodModerateJul 1220 µg/m³Nov 1612 µg/m³
PM2.5 (µg/m³)Level
Jan13Moderate
Feb16Moderate
Mar17Moderate
Apr17Moderate
May18Moderate
Jun19Moderate
Jul20Moderate
Aug17Moderate
Sep16Moderate
Oct13Moderate
Nov11Good
Dec13Moderate
Location & terrain

Where is Wilton?

Wilton sits at 41.2°N, 73.4°W, 249 ft above sea level, in United States. The nearest listed city is New Canaan, 4.3 mi away.

Topography around Wilton

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

Within 2 miles, the terrain around Wilton has only modest variations in elevation — a maximum elevation change of 440 ft around an average of 344 ft above sea level; within 10 miles, significant variations in elevation — a maximum elevation change of 1,024 ft; within 50 miles, significant variations in elevation — a maximum elevation change of 1,913 ft.

The land around Wilton is covered by trees (87%) within 2 miles, trees (83%) within 10 miles, and trees (61%) and water (24%) within 50 miles.

2 miles
440 ft
10 miles
1,024 ft
50 miles
1,913 ft
treesgrasslandcroplandartificial surfaceswaterwetland
December weather nearby: New Canaan 4.3 mi · Westport 5.6 mi · Norwalk 5.6 mi · East Norwalk 6.8 mi · North Stamford 6.8 mi · Darien 8.1 mi · Fairfield 9.9 mi · Stamford 11 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 Wilton (41.1954°, -73.4379°, elevation 249 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). Sea temperatures are the NOAA OISST v2.1 1991–2020 monthly climatology (public domain), sampled at the nearest ocean point. 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).