Frankfort weather in December

In December, Frankfort sees average daytime highs of 37°F and overnight lows near 24°F, with 2.2 in of precipitation across 8 wet days and about 9.1 hours of daylight. It is the 10th-warmest and 11th-wettest month of the year here.

Highs ease over the month, from about 41°F in the first days to 34°F by the end. The sky is clear or mostly clear about 21% 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 hours by month's end. Set against the rest of the year, December is Frankfort's 11th-clearest and 6th-windiest month. For the whole year in context, see Frankfort's year-round climate.

Daytime high
37°
10th warmest
Overnight low
24°
3rd coldest
Precipitation
2.2 in
8 wet days
Daylight
9 hours
7:17 AM – 4:18 PM
Cloud cover
70%
11th clearest
Wind
9 mph
6th windiest
Solar energy
1.66 kWh/m²
Travel score
0.0
out of 10

Frankfort is village on border of Cook and Will Counties in Illinois, United States of America.

Founded
1879

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 41°F in the first days to 34°F by the end.

A typical December day in Frankfort reaches about 37°F in the afternoon and slips back to 24°F overnight — a 12°F spread between the day's warmth and the night's chill. On most days the high lands between 22°F and 51°F. Set against its neighbours, December runs about 12°F cooler than November and about 5°F warmer than January.

20°40°60°151015202531
Avg high (°F)Avg low (°F)
14228
24128
34028
44027
54027
63926
73926
83826
93826
103825
113725
123725
133724
143724
153624
163624
173624
183624
193623
203523
213523
223523
233523
243523
253522
263522
273522
283422
293422
303422
313421

How December really feels in Frankfort

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
15 feel bitter (≤ 14°F)

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

Frankfort weather by month

How December compares with the rest of the year at a glance. December is the 10th-warmest and 11th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°F)Rainfall (inches)Wet daysSnow daysDaylight (hours)Travel score
Jan32° / 19°2.38.75.79.30.0
Feb36° / 21°2.07.14.810.30.0
Mar47° / 31°2.910.6311.71.5
Apr59° / 41°4.412.60.913.14.3
May70° / 51°4.612.6014.36.0
Jun79° / 62°4.311.6014.96.3
Jul83° / 66°3.911.9014.75.8
Aug81° / 64°3.810.8013.76.5
Sep75° / 56°3.08.5012.37.1
Oct62° / 44°3.29.50.110.95.4
Nov48° / 34°2.78.61.29.71.9
Dec37° / 24°2.283.99.10.0

Cloud cover in December

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 21% of the time in December.

Beyond those clear spells, partly cloudy skies cover about 10% of December, with mostly cloudy or overcast conditions the remaining 68%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
13565
23466
33466
43466
53367
63466
73466
83367
93367
103367
113367
123268
133268
143268
153268
163268
173169
183169
193169
203169
213169
223070
233070
242971
253070
263070
273070
283070
293070
302971
313070

Chance of precipitation in December

Any precipitationSnow

Frankfort gets around 2.2 in of rain and snow over 8 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 26% and peaks near 30% on the wettest days, and about 4 days bring snow.

0%10%20%30%40%151015202531
Rain chance (%)Snow chance (%)
13010
22911
32911
42911
52911
62812
72812
82812
92712
102712
112612
122612
132612
142612
152612
162612
172612
182512
192512
202512
212512
222412
232412
242413
252413
262413
272513
282513
292513
302514
312614

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
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 9 mph in December.

Across December, daily wind ranges from about 9 mph on the calmest days to 9 mph at its breeziest. It stays fairly steady from day to day.

051015151015202531
Wind speed (mph)Feels
19light breeze
29light breeze
39light breeze
49light breeze
59light breeze
69light breeze
79light breeze
89light breeze
99light breeze
109light breeze
119light breeze
129light breeze
139light breeze
149light breeze
159light breeze
169light breeze
179light breeze
189light breeze
199light breeze
209light breeze
219light breeze
229light breeze
239light breeze
249light breeze
259light breeze
269light breeze
279light breeze
289light breeze
299light breeze
309light breeze
319light breeze

Sunrise & sunset in December

DaylightNight

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

Days shrink by about 12 minutes over December. Sunrise moves from 7:05 AM to 7:23 AM, and sunset from 4:18 PM to 4:26 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
19.27:054:18
29.27:064:17
39.27:074:17
49.27:084:17
59.17:084:17
69.17:094:17
79.17:104:17
89.17:114:17
99.17:124:17
109.17:134:17
119.17:144:17
129.07:144:17
139.07:154:17
149.07:164:17
159.07:174:18
169.07:174:18
179.07:184:18
189.07:184:19
199.07:194:19
209.07:204:19
219.07:204:20
229.07:214:20
239.07:214:21
249.07:214:21
259.07:224:22
269.07:224:22
279.07:234:23
289.07:234:24
299.07:234:24
309.07:234:25
319.07:234:26

Solar energy in December

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in December, about 1.66 kWh/m² — the year's lowest.

For context, solar energy here swings from a low near 1.66 kWh/m² to a high of 6.5 kWh/m² in June across the year — December's 1.66 kWh/m² sits near the bottom.

00.511.522.5151015202531
Solar energy (kWh/m²)Level
11.8Dim
21.7Dim
31.7Dim
41.7Dim
51.7Dim
61.7Dim
71.7Dim
81.7Dim
91.7Dim
101.7Dim
111.7Dim
121.7Dim
131.6Dim
141.6Dim
151.6Dim
161.6Dim
171.6Dim
181.6Dim
191.6Dim
201.6Dim
211.6Dim
221.6Dim
231.6Dim
241.6Dim
251.6Dim
261.6Dim
271.6Dim
281.6Dim
291.6Dim
301.7Dim
311.7Dim
Planning a trip in December

Is December a good time to visit Frankfort?

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

0.0
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 Frankfort.

What to pack for Frankfort in December

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

In December, Frankfort sees daytime highs around 37°F and nights near 24°F. Pack a warm layer and a heavy coat. Worth having: rain gear. About 8 days see rain.

a warm layera heavy coatrain gear

Sea temperature near Frankfort in December

The nearest coast averages about 42°F in December — the other half of the beach question. The full-year curve and swim-comfort zones are below.

The sea at the nearest coast (about 26 mi away) is warmest in August at about 73°F and coldest in February near 35°F.

It's comfortable for a long swim from Jul 10 to Sep 16 — about 2.3 months when the water holds above 68°F.

30°40°50°60°70°80°JanFebMarAprMayJunJulAugSepOctNovDecbracingcoolrefreshingwarmcomfortable to swim
Sea temperature (°F)Comfort
Jan38Bracing
Feb35Bracing
Mar35Bracing
Apr39Bracing
May46Bracing
Jun59Cool
Jul70Refreshing
Aug73Refreshing
Sep68Refreshing
Oct58Bracing
Nov49Bracing
Dec42Bracing

UV index in Frankfort 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 Frankfort peaks around June 22 at about 9 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near December 21 at about 2 (low).

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

025710JanFebMarAprMayJunJulAugSepOctNovDecLowModerateHighVery highHighModerateLowJun 22UV 9Dec 21UV 2
UV index (midday)Level
Jan2Low
Feb3Moderate
Mar5Moderate
Apr6High
May7Very high
Jun9Very high
Jul9Very high
Aug8Very high
Sep6High
Oct3Moderate
Nov2Moderate
Dec2Low

Air quality in Frankfort 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 Frankfort is worst in July — around 18 µg/m³ PM2.5 (moderate), about 2.2× the cleanest month (October, 8 µg/m³).

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

0102030JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodJul 1418 µg/m³Oct 238 µg/m³
PM2.5 (µg/m³)Level
Jan11Good
Feb14Moderate
Mar15Moderate
Apr15Moderate
May17Moderate
Jun17Moderate
Jul18Moderate
Aug16Moderate
Sep12Moderate
Oct8Good
Nov9Good
Dec10Good
Location & terrain

Where is Frankfort?

Frankfort sits at 41.5°N, 87.8°W, 761 ft above sea level, in United States. The nearest listed city is Mokena, 3.1 mi away.

Topography around Frankfort

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

Within 2 miles, the terrain around Frankfort has only modest variations in elevation — a maximum elevation change of 131 ft around an average of 745 ft above sea level; within 10 miles, only modest variations in elevation — a maximum elevation change of 269 ft; within 50 miles, only modest variations in elevation — a maximum elevation change of 741 ft.

The land around Frankfort is covered by trees (33%), grassland (23%) and cropland (22%) within 2 miles, cropland (33%), trees (24%) and grassland (23%) within 10 miles, and cropland (47%) within 50 miles.

2 miles
131 ft
10 miles
269 ft
50 miles
741 ft
treesgrasslandcroplandartificial surfaceswater
December weather nearby: Mokena 3.1 mi · New Lenox 6.2 mi · Tinley Park 6.2 mi · Matteson 6.8 mi · Country Club Hills 8.1 mi · Homer Glen 8.7 mi · Park Forest 9.3 mi · Oak Forest 9.3 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 Frankfort (41.4959°, -87.8487°, elevation 761 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. 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).