Jacksonville weather in January

In January, Jacksonville sees average daytime highs of 36°F and overnight lows near 21°F, with 2.3 in of precipitation across 7.7 wet days and about 9.5 hours of daylight. It is the 12th-warmest and 10th-wettest month of the year here.

Day-to-day highs hold fairly steady near 36°F through the month. The sky is clear or mostly clear about 27% of the time in January, and the air most often feels dry.

Daylight stretches from about 9 h 12 min at the start of January to 9 h 54 min by month's end. Set against the rest of the year, January is Jacksonville's 12th-clearest and 4th-windiest month. For the whole year in context, see Jacksonville's year-round climate.

Daytime high
36°
12th warmest
Overnight low
21°
1st coldest
Precipitation
2.3 in
7.7 wet days
Daylight
9 h 30 min
7:26 AM – 4:55 PM
Cloud cover
66%
12th clearest
Wind
9 mph
4th windiest
Solar energy
2.13 kWh/m²
Travel score
0.0
out of 10

Jacksonville is city in Morgan County, Illinois, United States.

Density
691/km²
people per km²
Founded
1825

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

Temperature in January

Average highAverage lowShaded bands: 10–90% of days

Day-to-day highs hold fairly steady near 36°F through the month.

A typical January day in Jacksonville reaches about 36°F in the afternoon and slips back to 21°F overnight — a 15°F spread between the day's warmth and the night's chill. On most days the high lands between 20°F and 52°F. Set against its neighbours, January runs about 5°F cooler than December and about 5°F cooler than February.

20°40°60°151015202531
Avg high (°F)Avg low (°F)
13723
23723
33723
43722
53722
63622
73622
83622
93621
103621
113621
123621
133521
143521
153520
163520
173520
183520
193520
203520
213520
223520
233620
243620
253621
263621
273621
283621
293721
303721
313721

How January really feels in Jacksonville

Once humidity and wind are folded in, January 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
31 feel bitter (≤ 14°F)

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

Jacksonville weather by month

How January compares with the rest of the year at a glance. January is the 12th-warmest and 10th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°F)Rainfall (inches)Wet daysSnow daysDaylight (hours)Travel score
Jan36° / 21°2.37.749.50.0
Feb41° / 24°2.27.23.410.40.3
Mar52° / 34°3.110.31.611.72.8
Apr64° / 45°4.611.50.4135.4
May74° / 55°4.413.4014.26.2
Jun82° / 65°4.111.1014.85.8
Jul85° / 68°3.39.5014.55.3
Aug84° / 66°3.09013.65.7
Sep78° / 58°2.97.5012.37.3
Oct66° / 46°3.08.30.110.96.3
Nov52° / 35°3.28.20.99.82.8
Dec40° / 26°2.37.42.79.20.2

Cloud cover in January

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 27% of the time in January, the cloudiest month of the year.

Beyond those clear spells, partly cloudy skies cover about 11% of January, with mostly cloudy or overcast conditions the remaining 62%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
13664
23664
33664
43763
53763
63664
73664
83763
93763
103763
113862
123862
133862
143961
153862
163862
173961
183961
193961
203961
213961
224060
233961
243961
253961
263961
273961
283862
293961
303961
313961

Chance of precipitation in January

Any precipitationSnow

Jacksonville gets around 2.3 in of rain and snow over 7.7 wet days in January. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable precipitation averages around 24% and peaks near 26% on the wettest days, and about 4 days bring snow.

0%10%20%30%40%151015202531
Rain chance (%)Snow chance (%)
12310
22311
32411
42411
52512
62512
72512
82612
92613
102613
112613
122613
132613
142613
152613
162613
172513
182513
192513
202413
212413
222413
232313
242313
252313
262313
272213
282213
292213
302213
312213

Humidity in January

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, January 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 (%)
1100
2100
3100
4100
5100
6100
7100
8100
9100
10100
11100
12100
13100
14100
15100
16100
17100
18100
19100
20100
21100
22100
23100
24100
25100
26100
27100
28100
29100
30100
31100

Wind in January

Winds average 9 mph in January.

Across January, 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 January

DaylightNight

Daylight runs from about 9 h 12 min at the start of January to 9 h 54 min by month's end. The lit band spans sunrise to sunset each day.

Days grow by about 42 minutes over January. Sunrise moves from 7:27 AM to 7:17 AM, and sunset from 4:41 PM to 5:11 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
19.27:274:41
29.27:274:42
39.37:274:43
49.37:274:43
59.37:274:44
69.37:284:45
79.37:274:46
89.37:274:47
99.37:274:48
109.47:274:49
119.47:274:50
129.47:274:51
139.47:274:52
149.47:264:53
159.57:264:54
169.57:264:55
179.57:264:56
189.57:254:57
199.57:254:58
209.67:244:59
219.67:245:00
229.67:235:01
239.77:235:02
249.77:225:03
259.77:225:04
269.77:215:05
279.87:205:07
289.87:205:08
299.87:195:09
309.97:185:10
319.97:175:11

Solar energy in January

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in January, about 2.13 kWh/m².

For context, solar energy here swings from a low near 1.84 kWh/m² to a high of 6.46 kWh/m² in June across the year — January's 2.13 kWh/m² sits near the bottom.

0123151015202531
Solar energy (kWh/m²)Level
11.9Dim
21.9Dim
31.9Dim
41.9Dim
51.9Dim
61.9Dim
71.9Dim
82.0Dim
92.0Dim
102.0Moderate
112.0Moderate
122.0Moderate
132.1Moderate
142.1Moderate
152.1Moderate
162.1Moderate
172.2Moderate
182.2Moderate
192.2Moderate
202.2Moderate
212.3Moderate
222.3Moderate
232.3Moderate
242.3Moderate
252.4Moderate
262.4Moderate
272.4Moderate
282.5Moderate
292.5Moderate
302.5Moderate
312.6Moderate
Planning a trip in January

Is January a good time to visit Jacksonville?

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

0.0
Sightseeing
12th-best month of the year
0.0
Beach & pool
10th-best month of the year

January is a weaker month for outdoor sightseeing in Jacksonville.

What to pack for Jacksonville in January

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

In January, Jacksonville sees daytime highs around 36°F and nights near 21°F. Pack a warm layer and a heavy coat. About 8 days see rain.

a warm layera heavy coat

UV index in Jacksonville in January

LowModerateHighVery highExtreme

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

Under clear skies, the midday UV index in Jacksonville peaks around June 21 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 10 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecModerateHighVery highModerateJun 21UV 9Dec 22UV 2
UV index (midday)Level
Jan2Low
Feb3Moderate
Mar5Moderate
Apr6High
May8Very high
Jun9Very high
Jul9Very high
Aug8Very high
Sep7High
Oct4Moderate
Nov3Moderate
Dec2Low

Air quality in Jacksonville in January

GoodModeratePoorUnhealthyVery unhealthy

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

Air quality in Jacksonville is worst in July — around 16 µg/m³ PM2.5 (moderate), about 2.2× the cleanest month (October, 8 µg/m³).

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

01020JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodModerateGoodJul 1716 µg/m³Oct 238 µg/m³
PM2.5 (µg/m³)Level
Jan10Good
Feb13Moderate
Mar12Moderate
Apr11Good
May14Moderate
Jun14Moderate
Jul16Moderate
Aug14Moderate
Sep11Good
Oct8Good
Nov8Good
Dec9Good
Location & terrain

Where is Jacksonville?

Jacksonville sits at 39.7°N, 90.2°W, 610 ft above sea level, in United States. The nearest listed city is Springfield, 32 mi away.

Topography around Jacksonville

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

Within 2 miles, the terrain around Jacksonville has only modest variations in elevation — a maximum elevation change of 177 ft around an average of 604 ft above sea level; within 10 miles, only modest variations in elevation — a maximum elevation change of 243 ft; within 50 miles, only modest variations in elevation — a maximum elevation change of 604 ft.

The land around Jacksonville is covered by trees (32%), grassland (25%) and cropland (23%) within 2 miles, cropland (74%) within 10 miles, and cropland (65%) and trees (27%) within 50 miles.

2 miles
177 ft
10 miles
243 ft
50 miles
604 ft
treesgrasslandcroplandartificial surfacesbare terrainwater
January weather nearby: Springfield 32 mi · Godfrey 54 mi · Macomb 55 mi · Upper Alton 57 mi · Alton 58 mi · Hannibal 60 mi · Old Jamestown 62 mi · Quincy 64 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 Jacksonville (39.7339°, -90.229°, elevation 610 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. 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).