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Shaded-relief map of Diamond, Illinois: rivers, roads, the city limits and where the water drains.
ILLINOIS · GRUNDY COUNTY

Diamond

2,702 people, 560 ft above sea level in Grundy County.

560 ftElevation, city center
2,702People, 2024 estimate
2 sq miLand area
Clear 38°
Clear now Dew point 28° · WNW 6 mph · high 37°
City of Diamond River Interstate 2 miles
Explore the plate Order a print

The Diamond 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 Diamond

NWS forecast and National Blend of Models · updated 5:00 PM CST
RIGHT NOW Greater Kankakee Airport (KIKK) · 5:35 PM
Clear
38° Clear Feels like 34° · high of 37° near 5 PM
WindWNW 6 mphno gusts
Humidity67%rising to 100% by morning
Pressure30.29 in →steady
Visibility10 mihaze-free
CloudsClear
UV index—no forecast
Dew point 28° · Dryabout the same for three days
DryComfortableStickyMuggyOppressive
NEXT RAIN
Clear
Not this weeknone in the forecast for a week
LIKELY AMOUNT—nothing expected
LAST RAINNov. 130.02 in · 1 dry day
ALERTS & OUTLOOKS
No watches or warnings for Grundy County
NWS Chicago and the Storm Prediction Center · checked 5:45 PM
SUN & MOON
↑ 6:39 AM4:35 PM ↓
9 h 55 m of daylight, 2 minutes less than yesterday
Waxing crescent, 26% lit. Next full moon: Nov. 24.
AIR & POLLEN
24
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
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
mostly clear night
clear night
mostly clear night
mostly clear night
clear day
clear day
clear day
mostly clear night
mostly clear night
mostly clear night
mostly clear night
mostly clear night
clear day
clear day
clear day
mostly clear night
mostly clear night
clear night
mostly clear night
mostly clear night
mostly sunny
clear day
clear day
TEMPERATURE °F
37°
26°
48°
26°
50°
29°
CHANCE OF RAIN
50%
WIND, MPH
5
2
0
2
0
0
0
0
0
0
0
0
0
0
6
5
2
3
3
5
3
6
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8
HOW IT FEELS · DEW POINT
Dry: dew points 26 to 34°

The next seven days, and how sure we are

Forecast, with the range 8 in 10 ensemble members agree on Normal, about 50° / 33°
SAT Nov. 14 Sunny Sunny
37° 25°
0% rain — WNW 3 A
SUN Nov. 15 Mostly sunny; warmer Mostly sunny; warmer
52° 25°
0% rain — WNW 0 A
MON Nov. 16 Sunny Sunny
55° 29°
0% rain — SW 3 A
TUE Nov. 17 Sunny Sunny
57° 32°
0% rain — S 6 A
WED Nov. 18 Partly cloudy Partly cloudy
60° 41°
0% rain — S 10 A
THU Nov. 19 Partly cloudy Partly cloudy
63° 43°
10% rain — WSW 7 B
FRI Nov. 20 Partly cloudy Partly cloudy
64° 46°
10% rain — SSE 7 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 Diamond about 5,000 feet above the ground was over the Canadian Prairies three days ago, and over the northern Plains a day ago, about 1,230 miles back along its path. Most of the nine paths traced from around the city agree. It rose from near the ground on the way. It has stayed over land, which is why it feels dry. 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 1911. Next is 4° in 1933.

4°
3°
19331959
Source: NOAA RCC-ACIS, the Morris 1 NW record since 1911.
MILE2
THE GROUND

What Diamond stands on

Diamond’s center stands about 560 ft above sea level. Within three miles the land runs from 540 ft to 600 ft, a difference of 60 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 4 rock units mapped at the surface.

Diamond, cut in half from southwest to northeast

A section southwest to northeast, 24 miles through the town center
500 ft600 ft DIAMOND560 ftMazon Riverabout 560 ftCoal City570 ftKankakee Riverabout 510 ftHigh point of the line680 ft ← SWElwood · NE →

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 15 mi of the line.

Silurian System undivided

Dolostone, limestone. Age: Silurian, 422 to 445 million years old. About 7 mi of the line.

Tradewater Formation

Shale, sandstone. Age: Early Pennsylvanian to Middle Pennsylvanian, 307 to 324 million years old. About 1 mi of the line.

Maquoketa Formation or Group

Shale, limestone. Age: Late Ordovician, 445 to 454 million years old. About 0.8 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 Diamond’s rain goes

A raindrop that lands in Diamond reaches the Gulf of America by way of the Mazon, the Illinois and the Mississippi: about 1,470 river miles.

THE WAY DOWN, TO SCALE
Diamond≈ 1,470 mi · the Gulf of America
FROM THE CENTER OF DIAMOND ≈ 1,470 mi to the Gulf of America Mazon → Illinois → Mississippi

Lake on the way: Peoria Lake.

1,190 miles of the trip are on the Mississippi.

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

MILE5
THE ALMANAC

Diamond’s year

1991–2020 normals · records since 1911 · Morris 1 NW, 11 mi west-northwest

Diamond has a hot-summer humid continental climate. Summer afternoons average 85° in July; winter nights fall to about 16° in January. A normal year brings about 25 inches of snow; with the rain, that comes to about 39 inches of water.

31°16°36°19°48°29°61°40°72°51°82°61°85°65°83°63°77°55°64°43°49°32°37°22° JANFEBMARAPRMAYJUNJULAUGSEPOCTNOVDEC 1234 TODAY DIAMOND 38.8 in rain and snowmelt
Normal high to low, by month Record high to low, by day Rain by month Freezing
July, average85° / 65°high / low, the warmest month
January, average31° / 16°high / low, the coldest month
Rain and melted snow38.8 inwettest months: July and June
Snow a year24.7 insnowiest: February
Hottest on record109°FJuly 14, 1936
Coldest on record−26°FDecember 28, 1924
Wettest day on record6.51 inSeptember 28, 2019
Snowiest day on record12.0 inFebruary 7, 1933
90° days a year20very few reach 100°
Nights at or below 32°127and 43 days that stay below freezing
Climate typeHot-summer humid continentalKöppen Dfa

AROUND THE RING

1Freeze seasonfrom the first fall freeze, about Oct. 18, to the last in spring, about April 21 (median dates)
2Highs below freezingJan. 1 to Feb. 4; normal highs stay below 32°
3Lows below freezingNov. 13 to March 27; normal lows fall below 32°
4Wettest stretchMay through July: 14.0 of the year’s 38.8 inches
NOVEMBER 14 IN THE RECORD

On November 14 Diamond normally reaches 50° and falls to 32°. The record high is 74°, in 1999; the record low 5°, in 1996. The most rain on this date, 1.30 in, fell in 1926.

MONTH BY MONTH
JanFebMarAprMayJunJulAugSepOctNovDec
Normal high31°36°48°61°72°82°85°83°77°64°49°37°
Normal low16°19°29°40°51°61°65°63°55°43°32°22°
Rain and melt, in2.091.792.233.344.394.724.924.013.553.232.502.02
Snow, inches7.47.52.90.50.00.00.00.00.00.01.15.3
Record high68° (1950)74° (2024)85° (2012)93° (1930)103° (1934)106° (1934)109° (1936)107° (1934)103° (1939)95° (1963)82° (1950)72° (2012)
Record low−23° (2019)−22° (1996)−19° (1943)12° (1920)24° (1932)34° (1956)41° (1940)34° (1946)26° (1942)12° (1925)−9° (1950)−26° (1924)

Normals 1991–2020 and records since 1911 at Morris 1 NW, 11 miles west-northwest. NOAA, through RCC-ACIS.

MILE7
ON THE NETWORK

Around Diamond on the Forecast Network

Neighboring plates

Naperville IL · 32 MI 32 miles north Aurora IL · 33 MI 33 miles north Chicago IL · 48 MI 48 miles northeast Milwaukee WI · 124 MI 124 miles north Madison WI · 138 MI 138 miles northwest Indianapolis IN · 152 MI 152 miles southeast
FORECASTCITY
Map of Diamond, Illinois. Explore the plate
ILLINOIS · GRUNDY

Diamond

2,702 people, 560 ft above sea level in Grundy County.

560 ftElevation
2,702People
2 sq miLand
Clear 38°
ClearDew point 28°
1

Today in Diamond

NEXT 15 HOURS
Now clear night 37° 0%
8p clear night 33° 0%
11p clear night 29° 0%
2a mostly clear night 27° 0%
5a mostly clear night 26° 0%
8a mostly sunny 32° 0%
Clear
NEXT RAINNone this week
→
Sat0%
Sunny Sunny
25
37
A
Sun0%
Mostly sunny; warmer Mostly sunny; warmer
25
52
A
Mon0%
Sunny Sunny
29
55
A
Tue0%
Sunny Sunny
32
57
A
Wed0%
Partly cloudy Partly cloudy
41
60
A
Thu10%
Partly cloudy Partly cloudy
43
63
B
Fri10%
Partly cloudy Partly cloudy
46
64
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 1911.

2

What Diamond stands on

Diamond’s center stands about 560 ft above sea level. Within three miles the land runs from 540 ft to 600 ft, a difference of 60 ft: gently rolling country.

Diamond, southwest to northeast Diamond560 ftMazon Riverabout 560 ftKankakee Riverabout 510 ftHigh point680 ft ← SWNE → 24 miles through the town center; vertical exaggeration about 122×. Colors: rock at the surface.
Elevation, center560 ft
Within 3 miles540 to 600 ft
Lie of the landGently rolling (60 ft of relief)
Rock at the surfaceCarbondale Formation
Its ageMiddle Pennsylvanian to Late Pennsylvanian, 304 to 315 million years old
5

Diamond’s year

Diamond has a hot-summer humid continental climate. Summer afternoons average 85° in July; winter nights fall to about 16° in January. A normal year brings about 25 inches of snow; with the rain, that comes to about 39 inches of water.

JANFEBMARAPRMAYJUNJULAUGSEPOCTNOVDEC 1234 38.8 in
July, average85° / 65° · high / low, the warmest month
January, average31° / 16° · high / low, the coldest month
Rain and melted snow38.8 in · wettest months: July and June
Snow a year24.7 in · snowiest: February
Hottest on record109°F · July 14, 1936
Coldest on record−26°F · December 28, 1924
Wettest day on record6.51 in · September 28, 2019
Snowiest day on record12.0 in · February 7, 1933
90° days a year20 · very few reach 100°
Nights at or below 32°127 · and 43 days that stay below freezing
Climate typeHot-summer humid continental · Köppen Dfa
1Freeze season · from the first fall freeze, about Oct. 18, to the last in spring, about April 21 (median dates)
2Highs below freezing · Jan. 1 to Feb. 4; normal highs stay below 32°
3Lows below freezing · Nov. 13 to March 27; normal lows fall below 32°
4Wettest stretch · May through July: 14.0 of the year’s 38.8 inches
NOVEMBER 14 IN THE RECORD

On November 14 Diamond normally reaches 50° and falls to 32°. The record high is 74°, in 1999; the record low 5°, in 1996. The most rain on this date, 1.30 in, fell in 1926.

Normals 1991–2020 and records since 1911 at Morris 1 NW, 11 miles west-northwest. NOAA, through RCC-ACIS.
3

Where the rain goes

≈ 1,470 mito the Gulf of AmericaMazon → Illinois → Mississippi

A raindrop that lands in Diamond reaches the Gulf of America by way of the Mazon, the Illinois and the Mississippi: about 1,470 river miles.

Lake on the way: Peoria Lake.

1,190 miles of the trip are on the Mississippi.