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

Chemung

276 people, 900 ft above sea level in McHenry County.

900 ftElevation, city center
276People, 2024 estimate
0 sq miLand area
Sunny 48°
Sunny now Dew point 27° · NNW 8 mph · high 43°
City of Chemung River Interstate 2 miles
Explore the plate Order a print

The Chemung 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 Chemung

NWS forecast and National Blend of Models · updated 2:00 PM CST
RIGHT NOW Janesville-Rock County (KJVL) · 2:45 PM
Sunny
48° Sunny Feels like 45° · high of 43° near 3 PM
WindNNW 8 mphno gusts
Humidity43%rising to 96% by morning
Pressure30.25 in →steady
Visibility10 mihaze-free
CloudsClear
UV index—no forecast
Dew point 27° · Dryabout the same for three days
DryComfortableStickyMuggyOppressive
NEXT RAIN
Showers
Friday40% chance · showers
LIKELY AMOUNT—amounts come within 3 days
LAST RAINNov. 60.01 in · 8 dry days
ALERTS & OUTLOOKS
No watches or warnings for McHenry County
NWS Chicago and the Storm Prediction Center · checked 3:16 PM
SUN & MOON
↑ 6:44 AM4:34 PM ↓
9 h 49 m of daylight, 2 minutes less than yesterday
Waxing crescent, 25% lit. Next full moon: Nov. 24.
AIR & POLLEN
11
GOODAir quality index · fine particles
Tomorrow: None, moderate. 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
3p
6p
9p
Mid
3a
6a
9a
Noon
3p
6p
9p
Mid
3a
6a
9a
Noon
3p
6p
9p
Mid
3a
6a
9a
Noon
clear day
clear night
mostly clear night
mostly clear night
partly cloudy night
mostly sunny
mostly sunny
clear day
clear day
mostly clear night
mostly clear night
mostly clear night
mostly clear night
mostly sunny
mostly sunny
mostly sunny
mostly sunny
mostly clear night
clear night
clear night
mostly clear night
mostly sunny
mostly sunny
mostly sunny
TEMPERATURE °F
43°
25°
47°
25°
49°
32°
CHANCE OF RAIN
50%
WIND, MPH
6
0
0
0
0
0
0
0
0
0
0
0
0
2
7
10
10
8
7
6
6
7
9
11
HOW IT FEELS · DEW POINT
Dry: dew points 23 to 34°

The next seven days, and how sure we are

Forecast, with the range 8 in 10 ensemble members agree on Normal, about 47° / 29°
SAT Nov. 14 Sunny Sunny
43° 23°
0% rain — NNW 6 A
SUN Nov. 15 Mostly sunny Mostly sunny
49° 24°
0% rain — N 0 A
MON Nov. 16 Mostly sunny Mostly sunny
52° 30°
0% rain — SW 8 A
TUE Nov. 17 Mostly sunny Mostly sunny
55° 34°
0% rain — S 10 A
WED Nov. 18 Partly cloudy Partly cloudy
56° 43°
10% rain — S 14 B
THU Nov. 19 Partly cloudy Partly cloudy
59° 41°
20% rain — WSW 8 C
FRI Nov. 20 Chance of showers Chance of showers
59° 47°
40% rain up to 0.08″ SE 10 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 Chemung about 5,000 feet above the ground was over the Gulf of Alaska three days ago, and over the northern Plains a day ago, about 2,990 miles back along its path. It came down from about 14,000 feet up, warming and drying as it sank. Near the ground the air came from British Columbia; at 10,000 feet, from the Canadian Prairies. 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, FOUR YEARS AGO Nov. 11, 2022

The hottest this week has been

75° on Nov. 11, 2022, the hottest reading for this week of the year since 1945. Next is 71° in 1964.

71°
75°
19642022
Source: NOAA RCC-ACIS, the Lake Geneva Wwtp record since 1945.
MILE2
THE GROUND

What Chemung stands on

Chemung’s center stands about 900 ft above sea level. Within three miles the land runs from 850 ft to 970 ft, a difference of 120 ft: gently rolling country.

Under the town center the state geologic map shows Silurian System undivided (dolostone, limestone), from the Silurian, 422 to 445 million years old.

The section below crosses 6 rock units mapped at the surface.

Chemung, cut in half from southwest to northeast

A section southwest to northeast, 24 miles through the town center
800 ft900 ft1,000 ft1,100 ft CHEMUNG900 ftPiscasaw Creekabout 780 ftHarvard900 ftHigh point of the line1,150 ftLinn1,020 ft ← SWLinn · NE →

Heights every 0.1 mile from the Copernicus GLO-90 surface model; vertical exaggeration about 52×. 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

Galena Group (Trenton Limestone)

Dolostone, limestone. Age: Late Ordovician, 447 to 459 million years old. About 9 mi of the line.

Silurian System undivided

Dolostone, limestone. Age: Silurian, 422 to 445 million years old. About 8 mi of the line.

Maquoketa Formation

Shale, dolostone. Age: Ordovician, 445 to 487 million years old. About 3 mi of the line.

Maquoketa Formation or Group

Shale, limestone. Age: Late Ordovician, 445 to 454 million years old. About 2 mi of the line.

Silurian, undivided

Dolostone. Age: Silurian, 422 to 445 million years old. About 2 mi of the line.

Platteville Group

Dolostone, limestone. Age: Late Ordovician, 454 to 459 million years old. About 1 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 Chemung’s rain goes

A raindrop that lands in Chemung reaches the Gulf of America by way of Piscasaw Creek, the Kishwaukee, the Rock River and the Mississippi: about 1,630 river miles.

THE WAY DOWN, TO SCALE
Chemung≈ 1,630 mi · the Gulf of America
FROM THE CENTER OF CHEMUNG ≈ 1,630 mi to the Gulf of America Piscasaw Creek → Kishwaukee → Rock River → Mississippi

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

MILE5
THE ALMANAC

Chemung’s year

1991–2020 normals · records since 1945 · Lake Geneva Wwtp, 18 mi northeast

Chemung has a hot-summer humid continental climate. Summer afternoons average 86° in July; winter nights fall to about 15° in January. A normal year brings about 40 inches of snow; with the rain, that comes to about 37 inches of water.

30°15°35°17°45°26°59°37°72°48°81°58°86°63°83°61°76°54°63°42°47°31°35°21° JANFEBMARAPRMAYJUNJULAUGSEPOCTNOVDEC 123 TODAY CHEMUNG 36.9 in rain and snowmelt
Normal high to low, by month Record high to low, by day Rain by month Freezing
July, average86° / 63°high / low, the warmest month
January, average30° / 15°high / low, the coldest month
Rain and melted snow36.9 inwettest months: June and May
Snow a year40.1 insnowiest: January
Hottest on record106°FAugust 1, 1988
Coldest on record−27°FJanuary 18, 1994
Wettest day on record4.96 inSeptember 12, 2022
Snowiest day on record13.2 inJanuary 26, 1978
Climate typeHot-summer humid continentalKöppen Dfa

AROUND THE RING

1Highs below freezingDec. 26 to Feb. 8; normal highs stay below 32°
2Lows below freezingNov. 12 to April 3; normal lows fall below 32°
3Wettest stretchMay through July: 12.7 of the year’s 36.9 inches
NOVEMBER 14 IN THE RECORD

On November 14 Chemung normally reaches 48° and falls to 31°. The record high is 70°, in 1971; the record low 8°, in 1959. The most rain on this date, 1.13 in, fell in 1957.

MONTH BY MONTH
JanFebMarAprMayJunJulAugSepOctNovDec
Normal high30°35°45°59°72°81°86°83°76°63°47°35°
Normal low15°17°26°37°48°58°63°61°54°42°31°21°
Rain and melt, in1.901.892.293.454.124.813.723.323.653.012.482.31
Snow, inches13.98.14.82.60.00.00.00.00.00.23.47.1
Record high59° (1997)74° (2024)81° (1986)90° (1980)94° (1991)104° (1988)104° (1995)106° (1988)100° (1953)87° (2025)75° (2022)67° (2001)
Record low−27° (1994)−25° (1996)−15° (1962)9° (1982)26° (1947)34° (1945)39° (1965)40° (1986)28° (1995)17° (1988)−6° (1950)−23° (1983)

Normals 1991–2020 and records since 1945 at Lake Geneva Wwtp, 18 miles northeast. NOAA, through RCC-ACIS.

MILE7
ON THE NETWORK

Around Chemung on the Forecast Network

Neighboring plates

Rockford IL · 23 MI 23 miles southwest Elgin IL · 31 MI 31 miles southeast Milwaukee WI · 57 MI 57 miles northeast Madison WI · 61 MI 61 miles northwest Chicago IL · 64 MI 64 miles southeast Grand Rapids MI · 158 MI 158 miles east
FORECASTCITY
Map of Chemung, Illinois. Explore the plate
ILLINOIS · MCHENRY

Chemung

276 people, 900 ft above sea level in McHenry County.

900 ftElevation
276People
0 sq miLand
Sunny 48°
SunnyDew point 27°
1

Today in Chemung

NEXT 15 HOURS
Now clear day 43° 0%
6p clear night 36° 0%
9p clear night 31° 0%
12a mostly clear night 28° 0%
3a partly cloudy night 26° 0%
6a mostly clear night 25° 0%
Showers
NEXT RAINFriday · 40%
→
Sat0%
Sunny Sunny
23
43
A
Sun0%
Mostly sunny Mostly sunny
24
49
A
Mon0%
Mostly sunny Mostly sunny
30
52
A
Tue0%
Mostly sunny Mostly sunny
34
55
A
Wed10%
Partly cloudy Partly cloudy
43
56
B
Thu20%
Partly cloudy Partly cloudy
41
59
C
Fri40%
Chance of showers Chance of showers
47
59
C
Letters show how sure the forecast is: A, models agree; B, some spread; C, check back. Sample data.
THIS WEEK, FOUR YEARS AGO · NOV. 11, 2022

75°, the hottest this week of the year has been since 1945.

2

What Chemung stands on

Chemung’s center stands about 900 ft above sea level. Within three miles the land runs from 850 ft to 970 ft, a difference of 120 ft: gently rolling country.

Chemung, southwest to northeast Chemung900 ftPiscasaw Creekabout 780 ft ← SWNE → 24 miles through the town center; vertical exaggeration about 100×. Colors: rock at the surface.
Elevation, center900 ft
Within 3 miles850 to 970 ft
Lie of the landGently rolling (120 ft of relief)
Rock at the surfaceSilurian System undivided
Its ageSilurian, 422 to 445 million years old
5

Chemung’s year

Chemung has a hot-summer humid continental climate. Summer afternoons average 86° in July; winter nights fall to about 15° in January. A normal year brings about 40 inches of snow; with the rain, that comes to about 37 inches of water.

JANFEBMARAPRMAYJUNJULAUGSEPOCTNOVDEC 123 36.9 in
July, average86° / 63° · high / low, the warmest month
January, average30° / 15° · high / low, the coldest month
Rain and melted snow36.9 in · wettest months: June and May
Snow a year40.1 in · snowiest: January
Hottest on record106°F · August 1, 1988
Coldest on record−27°F · January 18, 1994
Wettest day on record4.96 in · September 12, 2022
Snowiest day on record13.2 in · January 26, 1978
Climate typeHot-summer humid continental · Köppen Dfa
1Highs below freezing · Dec. 26 to Feb. 8; normal highs stay below 32°
2Lows below freezing · Nov. 12 to April 3; normal lows fall below 32°
3Wettest stretch · May through July: 12.7 of the year’s 36.9 inches
NOVEMBER 14 IN THE RECORD

On November 14 Chemung normally reaches 48° and falls to 31°. The record high is 70°, in 1971; the record low 8°, in 1959. The most rain on this date, 1.13 in, fell in 1957.

Normals 1991–2020 and records since 1945 at Lake Geneva Wwtp, 18 miles northeast. NOAA, through RCC-ACIS.
3

Where the rain goes

≈ 1,630 mito the Gulf of AmericaPiscasaw Creek → Kishwaukee → Rock River → Mississippi

A raindrop that lands in Chemung reaches the Gulf of America by way of Piscasaw Creek, the Kishwaukee, the Rock River and the Mississippi: about 1,630 river miles.