FORECAST CITY
Sign in
Shaded-relief map of South Jacksonville, Illinois: rivers, roads, the city limits and where the water drains.
ILLINOIS · MORGAN COUNTY

South Jacksonville

3,197 people, 620 ft above sea level in Morgan County.

620 ftElevation, city center
3,197People, 2024 estimate
2 sq miLand area
Clear 37°
Clear now Dew point 26° · Calm · high 38°
City of South Jacksonville River Interstate 2 miles
Explore the plate Order a print

The South Jacksonville plate. Relief from Copernicus GLO-30; rivers and lakes from USGS NHD; watersheds from the USGS Watershed Boundary Dataset; roads and city limits from Census TIGER 2024.

MILE1
TODAY

Today in South Jacksonville

NWS forecast and National Blend of Models · updated 5:00 PM CST
RIGHT NOW Jacksonville Municipal Airport (KIJX) · 5:35 PM
Clear
37° Clear Feels like 37° · high of 38° near 5 PM
WindCalmno gusts
Humidity64%rising to 100% by morning
Pressure30.31 in →steady
Visibility10 mihaze-free
CloudsClear
UV index—no forecast
Dew point 26° · Dry38° by Tuesday: more humid
DryComfortableStickyMuggyOppressive
NEXT RAIN
Clear
Not this weeknone in the forecast for a week
LIKELY AMOUNT—nothing expected
LAST RAINNov. 60.04 in · 8 dry days
ALERTS & OUTLOOKS
No watches or warnings for Morgan County
NWS Lincoln and the Storm Prediction Center · checked 5:46 PM
SUN & MOON
↑ 6:44 AM4:46 PM ↓
10 h 2 m of daylight, 2 minutes less than yesterday
Waxing crescent, 26% lit. Next full moon: Nov. 24.
AIR & POLLEN
13
GOODAir quality index · fine particles
Tomorrow: None, good. No pollen source yet.

The next three days, hour by hour

Sky: clear, cloudy, night Rain likely National Blend of Models
SATURDAY, NOV. 14
SUNDAY, NOV. 15
MONDAY, NOV. 16
TUESDAY, NOV. 17
5p
8p
11p
2a
5a
8a
11a
2p
5p
8p
11p
2a
5a
8a
11a
2p
5p
8p
11p
2a
5a
8a
11a
2p
clear night
clear night
clear night
mostly clear night
partly cloudy night
partly cloudy day
partly cloudy day
mostly sunny
clear night
mostly clear night
mostly clear night
clear night
mostly clear night
clear day
clear day
mostly sunny
mostly clear night
clear night
clear night
mostly clear night
mostly clear night
clear day
clear day
clear day
TEMPERATURE °F
38°
25°
49°
28°
52°
32°
CHANCE OF RAIN
50%
WIND, MPH
0
0
0
0
0
0
0
0
0
0
0
0
0
0
3
0
0
2
3
5
5
6
7
7
HOW IT FEELS · DEW POINT
Dry: dew points 24 to 38° More humid: 35° by Tuesday

The next seven days, and how sure we are

Forecast, with the range 8 in 10 ensemble members agree on Normal, about 80° / 62°
SAT Nov. 14 Sunny Sunny
38° 24°
0% rain — N 0 A
SUN Nov. 15 Partly cloudy; warmer Partly cloudy; warmer
52° 26°
0% rain — ENE 0 A
MON Nov. 16 Sunny Sunny
55° 30°
0% rain — SSW 1 A
TUE Nov. 17 Sunny Sunny
56° 34°
0% rain — SSE 6 A
WED Nov. 18 Mostly sunny Mostly sunny
59° 44°
10% rain — S 10 B
THU Nov. 19 Mostly sunny Mostly sunny
64° 45°
20% rain — WSW 5 C
FRI Nov. 20 Partly cloudy Partly cloudy
66° 50°
10% rain — SSE 8 C
How sure are we? AModels agree: highs within 4° BSome spread: within 8° CWide spread: check back
Range from the National Blend of Models percentiles · graded on Forecast Scores
AIR MAIL

Where today’s air came from

The air arriving over South Jacksonville about 5,000 feet above the ground was over the open Pacific three days ago, and over the central Plains a day ago, about 3,070 miles back along its path. It came down from about 15,400 feet up, warming and drying as it sank. Near the ground the air came from the Canadian Prairies; at 10,000 feet, from British Columbia. It feels dry all the same. Traced back 72 hours through NOAA’s hourly RAP analyses and the GFS beyond them, nine paths at each of three heights.

THIS WEEK IN 1959 Nov. 17, 1959

The coldest this week has been

3° on Nov. 17, 1959, the coldest reading for this week of the year since 1895. Next is 7° in 1986.

7°
3°
19861959
Source: NOAA RCC-ACIS, the Jacksonville 2 E record since 1895.
MILE2
THE GROUND

What South Jacksonville stands on

South Jacksonville’s center stands about 620 ft above sea level. Within three miles the land runs from 560 ft to 690 ft, a difference of 130 ft: gently rolling country.

Under the town center the state geologic map shows Carbondale Formation (shale, sandstone, coal), from the Middle Pennsylvanian to Late Pennsylvanian, 304 to 315 million years old.

The section below crosses 3 rock units mapped at the surface.

South Jacksonville, cut in half from south to north

A section south to north, 24 miles through the town center
500 ft600 ft700 ft SOUTH JACKSONVILLE620 ftHigh point of the line700 ftJacksonville600 ftMauvaise Terre Creekabout 550 ftIndian Creekabout 500 ftLow point500 ft ← SN →

Heights every 0.1 mile from the Copernicus GLO-90 surface model; vertical exaggeration about 64×. The colored band under the surface is the rock the state geologic map shows at the surface, not a picture of what lies beneath.

Rock at the surface along the line

Carbondale Formation

Shale, sandstone, coal. Age: Middle Pennsylvanian to Late Pennsylvanian, 304 to 315 million years old. About 13 mi of the line.

Shelburn-Patoka Formations undivided

Shale, limestone. Age: Late Pennsylvanian, 304 to 307 million years old. About 9 mi of the line.

Tradewater Formation

Shale, sandstone. Age: Early Pennsylvanian to Middle Pennsylvanian, 307 to 324 million years old. About 2 mi of the line.

From the USGS State Geologic Map Compilation (Horton and others, 2017), the states’ geologic maps joined at a common scale.

Heights from Copernicus GLO-90 (a surface model: it includes buildings and tree canopy); summits from USGS GNIS; rivers from USGS NHDPlus HR; rock from the USGS State Geologic Map Compilation.

MILE3
THE WATER

Where South Jacksonville’s rain goes

A raindrop that lands in South Jacksonville reaches the Gulf of America by way of Mauvaise Terre Creek, the Illinois and the Mississippi: about 1,290 river miles.

THE WAY DOWN, TO SCALE
South Jacksonville≈ 1,290 mi · the Gulf of America
FROM THE CENTER OF SOUTH JACKSONVILLE ≈ 1,290 mi to the Gulf of America Mauvaise Terre Creek → Illinois → Mississippi

Traced down the USGS NHDPlus V2.1 river network from the Census center point of South Jacksonville; river miles along the main stem, rounded.

MILE5
THE ALMANAC

South Jacksonville’s year

1991–2020 normals · records since 1895 · Jacksonville 2 E, 2 mi northeast

South Jacksonville has a hot-summer humid continental climate. Summer afternoons average 86° in July; winter nights fall to about 18° in January. A normal year brings about 16 inches of snow; with the rain, that comes to about 39 inches of water.

36°18°41°21°52°30°65°40°75°52°83°61°86°64°85°62°80°54°68°42°53°32°41°23° JANFEBMARAPRMAYJUNJULAUGSEPOCTNOVDEC 123 TODAY 39.2 in rain and snowmelt
Normal high to low, by month Record high to low, by day Rain by month Freezing
July, average86° / 64°high / low, the warmest month
January, average36° / 18°high / low, the coldest month
Rain and melted snow39.2 inwettest months: June and May
Snow a year16.2 insnowiest: January
Hottest on record114°FJuly 14, 1954
Coldest on record−28°FFebruary 27, 1934
Wettest day on record5.02 inSeptember 23, 1993
Snowiest day on record12.0 inFebruary 2, 2011
90° days a year28very few reach 100°
Nights at or below 32°128and 28 days that stay below freezing
Climate typeHot-summer humid continentalKöppen Dfa

AROUND THE RING

1Freeze seasonfrom the first fall freeze, about Oct. 15, to the last in spring, about April 19 (median dates)
2Lows below freezingNov. 14 to March 24; normal lows fall below 32°
3Wettest stretchApril through June: 14.0 of the year’s 39.2 inches
NOVEMBER 14 IN THE RECORD

On November 14 South Jacksonville normally reaches 54° and falls to 32°. The record high is 79°, in 1989; the record low 7°, in 1986. The most rain on this date, 1.58 in, fell in 1985.

MONTH BY MONTH
JanFebMarAprMayJunJulAugSepOctNovDec
Normal high36°41°52°65°75°83°86°85°80°68°53°41°
Normal low18°21°30°40°52°61°64°62°54°42°32°23°
Rain and melt, in1.931.722.814.274.824.893.963.393.502.973.011.98
Snow, inches5.14.32.00.30.00.00.00.00.00.01.03.5
Record high75° (1950)81° (2024)93° (2026)94° (1930)103° (1934)107° (1931)114° (1954)112° (1934)106° (1899)98° (1897)84° (2016)74° (2012)
Record low−24° (1927)−28° (1934)−14° (1948)10° (1920)26° (1966)36° (1993)43° (1930)39° (1986)23° (1899)9° (1925)−5° (1929)−21° (1914)

Normals 1991–2020 and records since 1895 at Jacksonville 2 E, 2 miles northeast. NOAA, through RCC-ACIS.

MILE7
ON THE NETWORK

Around South Jacksonville on the Forecast Network

Neighboring plates

Springfield IL · 31 MI 31 miles east St. Louis MO · 73 MI 73 miles south Columbia MO · 124 MI 124 miles southwest Cedar Rapids IA · 174 MI 174 miles northwest Evansville IN · 187 MI 187 miles southeast
FORECASTCITY
Map of South Jacksonville, Illinois. Explore the plate
ILLINOIS · MORGAN

South Jacksonville

3,197 people, 620 ft above sea level in Morgan County.

620 ftElevation
3,197People
2 sq miLand
Clear 37°
ClearDew point 26°
1

Today in South Jacksonville

NEXT 15 HOURS
Now clear night 38° 0%
8p clear night 33° 0%
11p clear night 29° 0%
2a clear night 27° 0%
5a mostly clear night 26° 0%
8a partly cloudy day 30° 0%
Clear
NEXT RAINNone this week
→
Sat0%
Sunny Sunny
24
38
A
Sun0%
Partly cloudy; warmer Partly cloudy; warmer
26
52
A
Mon0%
Sunny Sunny
30
55
A
Tue0%
Sunny Sunny
34
56
A
Wed10%
Mostly sunny Mostly sunny
44
59
B
Thu20%
Mostly sunny Mostly sunny
45
64
C
Fri10%
Partly cloudy Partly cloudy
50
66
C
Letters show how sure the forecast is: A, models agree; B, some spread; C, check back. Sample data.
THIS WEEK IN 1959 · NOV. 17, 1959

3°, the coldest this week of the year has been since 1895.

2

What South Jacksonville stands on

South Jacksonville’s center stands about 620 ft above sea level. Within three miles the land runs from 560 ft to 690 ft, a difference of 130 ft: gently rolling country.

South Jacksonville, south to north South Jacksonville620 ftHigh point700 ftMauvaise Terre Creekabout 550 ftIndian Creekabout 500 ft ← SN → 24 miles through the town center; vertical exaggeration about 122×. Colors: rock at the surface.
Elevation, center620 ft
Within 3 miles560 to 690 ft
Lie of the landGently rolling (130 ft of relief)
Rock at the surfaceCarbondale Formation
Its ageMiddle Pennsylvanian to Late Pennsylvanian, 304 to 315 million years old
5

South Jacksonville’s year

South Jacksonville has a hot-summer humid continental climate. Summer afternoons average 86° in July; winter nights fall to about 18° in January. A normal year brings about 16 inches of snow; with the rain, that comes to about 39 inches of water.

JANFEBMARAPRMAYJUNJULAUGSEPOCTNOVDEC 123 39.2 in
July, average86° / 64° · high / low, the warmest month
January, average36° / 18° · high / low, the coldest month
Rain and melted snow39.2 in · wettest months: June and May
Snow a year16.2 in · snowiest: January
Hottest on record114°F · July 14, 1954
Coldest on record−28°F · February 27, 1934
Wettest day on record5.02 in · September 23, 1993
Snowiest day on record12.0 in · February 2, 2011
90° days a year28 · very few reach 100°
Nights at or below 32°128 · and 28 days that stay below freezing
Climate typeHot-summer humid continental · Köppen Dfa
1Freeze season · from the first fall freeze, about Oct. 15, to the last in spring, about April 19 (median dates)
2Lows below freezing · Nov. 14 to March 24; normal lows fall below 32°
3Wettest stretch · April through June: 14.0 of the year’s 39.2 inches
NOVEMBER 14 IN THE RECORD

On November 14 South Jacksonville normally reaches 54° and falls to 32°. The record high is 79°, in 1989; the record low 7°, in 1986. The most rain on this date, 1.58 in, fell in 1985.

Normals 1991–2020 and records since 1895 at Jacksonville 2 E, 2 miles northeast. NOAA, through RCC-ACIS.
3

Where the rain goes

≈ 1,290 mito the Gulf of AmericaMauvaise Terre Creek → Illinois → Mississippi

A raindrop that lands in South Jacksonville reaches the Gulf of America by way of Mauvaise Terre Creek, the Illinois and the Mississippi: about 1,290 river miles.