Quincy weather in December

In December, Quincy sees average daytime highs of 40°F and overnight lows near 25°F, with 2.1 in of precipitation across 6.9 wet days and about 9.2 hours of daylight. It is the 11th-warmest and 11th-wettest month of the year here.

Highs ease over the month, from about 44°F in the first days to 37°F by the end. The sky is clear or mostly clear about 29% 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 Quincy's 9th-clearest and 6th-windiest month. For the whole year in context, see Quincy's year-round climate.

Daytime high
40°
11th warmest
Overnight low
25°
3rd coldest
Precipitation
2.1 in
6.9 wet days
Daylight
9 h 12 min
7:26 AM – 4:37 PM
Cloud cover
63%
9th clearest
Wind
8 mph
6th windiest
Solar energy
1.84 kWh/m²
Travel score
0.2
out of 10

Quincy is county seat of Adams County, Illinois, United States.

Density
988/km²
people per km²
Founded
1819

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 44°F in the first days to 37°F by the end.

A typical December day in Quincy reaches about 40°F in the afternoon and slips back to 25°F overnight — a 15°F spread between the day's warmth and the night's chill. On most days the high lands between 26°F and 55°F. Set against its neighbours, December runs about 11°F cooler than November and about 4°F warmer than January.

20°40°60°151015202531
Avg high (°F)Avg low (°F)
14529
24429
34429
44328
54328
64228
74227
84227
94127
104126
114126
124026
134026
144026
154025
164025
173925
183925
193925
203924
213824
223824
233824
243824
253823
263823
273823
283723
293723
303722
313722

How December really feels in Quincy

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
5 feel bitter (≤ 14°F)

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

Quincy weather by month

How December compares with the rest of the year at a glance. December is the 11th-warmest and 11th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°F)Rainfall (inches)Wet daysSnow daysDaylight (hours)Travel score
Jan36° / 20°1.97.24.29.50.0
Feb40° / 24°2.273.210.40.2
Mar52° / 34°2.99.61.811.72.8
Apr64° / 45°4.411.30.3135.4
May74° / 55°4.612.7014.26.3
Jun83° / 65°4.010.5014.85.8
Jul86° / 69°3.49014.55.2
Aug84° / 66°3.28.4013.65.7
Sep78° / 58°3.37.4012.37.3
Oct65° / 46°2.88.50.210.96.2
Nov51° / 35°2.97.60.99.82.8
Dec40° / 25°2.16.92.89.20.2

Cloud cover in December

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 29% of the time in December.

Beyond those clear spells, partly cloudy skies cover about 12% of December, with mostly cloudy or overcast conditions the remaining 60%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
14357
24258
34159
44258
54258
64258
74258
84258
94159
104159
114060
124060
134060
144060
154060
164060
173961
184060
194060
203961
213961
224060
234060
244060
254060
264060
274060
283961
293961
303961
313961

Chance of precipitation in December

Any precipitationSnow

Quincy gets around 2.1 in of rain and snow over 6.9 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 23% and peaks near 25% on the wettest days, and about 3 days bring snow.

0%10%20%30%40%151015202531
Rain chance (%)Snow chance (%)
1258
2258
3248
4248
5239
6239
7239
8239
9239
10229
11229
12229
13238
14238
15238
16238
17238
18238
19238
20238
21239
22229
23229
24229
25229
26229
272210
282210
292210
302211
312211

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 (%)
1982
2982
3991
4991
5991
6991
7991
8991
9991
10991
11991
12991
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 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 7:14 AM to 7:33 AM, and sunset from 4:37 PM to 4:45 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
19.47:144:37
29.47:154:36
39.37:164:36
49.37:174:36
59.37:184:36
69.37:194:36
79.37:204:36
89.37:204:36
99.27:214:36
109.27:224:36
119.27:234:36
129.27:244:36
139.27:244:36
149.27:254:37
159.27:264:37
169.27:264:37
179.27:274:38
189.27:284:38
199.27:284:38
209.27:294:39
219.27:294:39
229.27:304:39
239.27:304:40
249.27:314:40
259.27:314:41
269.27:314:42
279.27:324:42
289.27:324:43
299.27:324:43
309.27:334:44
319.27:334:45

Solar energy in December

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in December, about 1.84 kWh/m² — the year's lowest.

For context, solar energy here swings from a low near 1.84 kWh/m² to a high of 6.44 kWh/m² in June across the year — December's 1.84 kWh/m² sits near the bottom.

00.511.522.5151015202531
Solar energy (kWh/m²)Level
11.9Dim
21.9Dim
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
221.8Dim
231.8Dim
241.8Dim
251.8Dim
261.9Dim
271.9Dim
281.9Dim
291.9Dim
301.9Dim
311.9Dim
Planning a trip in December

Hazard calendar for Quincy

In seasonPeak

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

Quincy 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 Quincy?

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

0.2
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 Quincy.

What to pack for Quincy in December

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

In December, Quincy sees daytime highs around 40°F and nights near 25°F. Pack a warm layer and a heavy coat. About 7 days see rain.

a warm layera heavy coat

UV index in Quincy 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 Quincy peaks around June 20 at about 9 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near December 22 at about 2 (low).

The index reaches 3 or more — the level where the WHO recommends sun protection — in 9 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecModerateHighVery highHighModerateJun 20UV 9Dec 22UV 2
UV index (midday)Level
Jan2Low
Feb3Moderate
Mar5Moderate
Apr6High
May8Very high
Jun10Very high
Jul9Very high
Aug8Very high
Sep7High
Oct4Moderate
Nov3Moderate
Dec2Low

Air quality in Quincy 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 Quincy is worst in July — around 16 µg/m³ PM2.5 (moderate), about 2.3× the cleanest month (October, 7 µg/m³).

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

01020JanFebMarAprMayJunJulAugSepOctNovDecGoodGoodModerateGoodJul 1716 µg/m³Oct 237 µg/m³
PM2.5 (µg/m³)Level
Jan10Good
Feb12Moderate
Mar12Good
Apr10Good
May13Moderate
Jun14Moderate
Jul16Moderate
Aug14Moderate
Sep11Good
Oct7Good
Nov7Good
Dec8Good
Location & terrain

Where is Quincy?

Quincy sits at 39.9°N, 91.4°W, 568 ft above sea level, in United States. The nearest listed city is Hannibal, 16 mi away.

Topography around Quincy

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

Within 2 miles, the terrain around Quincy has only modest variations in elevation — a maximum elevation change of 230 ft around an average of 551 ft above sea level; within 10 miles, only modest variations in elevation — a maximum elevation change of 328 ft; within 50 miles, only modest variations in elevation — a maximum elevation change of 702 ft.

The land around Quincy is covered by trees (35%) and artificial surfaces (29%) within 2 miles, cropland (53%) and trees (26%) within 10 miles, and cropland (53%) and trees (32%) within 50 miles.

2 miles
230 ft
10 miles
328 ft
50 miles
702 ft
treesgrasslandcroplandartificial surfaceswater
December weather nearby: Hannibal 16 mi · Macomb 53 mi · Burlington 62 mi · Jacksonville 64 mi · Kirksville 65 mi · Wentzville 83 mi · Columbia 84 mi · O'Fallon 86 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 Quincy (39.9356°, -91.4099°, elevation 568 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).