What is the average water temperature in Illinois?

The current average water temperature across Illinois's monitored water bodies is 70.8°F.

🌡️

Illinois Water Temperatures

Q: What is the warmest lake in Illinois today?

Sugar Creek Near Springfield, Il at 84.4°F.

Current lake & river temperatures in Illinois — updated daily from USGS sensors.

With Data

70.8°F

State Avg

84.4°F

Warmest

84.4°F

Warmest

Sugar Creek Near Springfield, Il

70.8°F

State Average

100 water bodies

33.8°F

Coldest

Rock River Near Joslin, Il

🏊

Swimming Conditions

⚠️ Brisk — wetsuit recommended

Based on avg 70.8°F

🎣

Fishing Conditions

🎣 Peak — bass, crappie, catfish

Based on avg 70.8°F

Illinois — Ranked by Temperature

56 with data

#	Water Body	°F	°C	Condition	🏊	Date
1	Sugar Creek Near Springfield, Il River	84.4°	29.1°	☀️ Warm	🏊 Excellent	Jul 16
2	Sangamon River Near Oakford, Il River	82.2°	27.9°	☀️ Warm	🏊 Excellent	Jul 16
3	Salt Creek Near Greenview, Il River	81.9°	27.7°	☀️ Warm	🏊 Excellent	Jul 16
4	Little Wabash River At Main St At Carmi, Il River	81.7°	27.6°	☀️ Warm	🏊 Excellent	Jul 17
5	Sangamon River At Fisher, Il River	81°	27.2°	☀️ Warm	🏊 Excellent	Jul 15
6	Sangamon River At Monticello, Il River	80.1°	26.7°	☀️ Warm	🏊 Excellent	Jul 17
7	Salt Creek Near Rowell, Il River	79.7°	26.5°	☀️ Warm	✅ Good	Jul 15
8	Vermilion River Near Leonore, Il River	79.3°	26.3°	☀️ Warm	✅ Good	Jul 11
9	Big Muddy River At Rte 127 At Murphysboro, Il River	78.8°	26°	☀️ Warm	✅ Good	Jun 4
10	Sangamon River At Petersburg, Il River	78.1°	25.6°	☀️ Warm	✅ Good	Jul 22
11	Calumet Sag Channel At Blue Island, Il Lake	77.9°	25.5°	☀️ Warm	✅ Good	Aug 6
12	Illinois River At Florence, Il River	77.5°	25.3°	☀️ Warm	✅ Good	Jun 4
13	South Fork Sangamon River Near Rochester, Il River	77.2°	25.1°	☀️ Warm	✅ Good	Jul 14
14	Mackinaw River Near Green Valley, Il River	77°	25°	☀️ Warm	✅ Good	Aug 5
15	Sangamon River At Route 48 At Decatur, Il River	75.9°	24.4°	☀️ Warm	✅ Good	Jul 26
16	Hanson Gravel Pit At Culvert Near Morris, Il Lake	75.6°	24.2°	☀️ Warm	✅ Good	Jun 4
17	Des Plaines River At Channahon, Il River	75.4°	24.1°	☀️ Warm	✅ Good	Jun 4
18	Mississippi River At Dam 13 Near Fulton, Il River	75.4°	24.1°	☀️ Warm	✅ Good	Jun 5
19	Illinois River At Starved Rock, Il River	74.8°	23.8°	🌤️ Comfortable	✅ Good	Jun 2
20	Kankakee River At Custer Park, Il River	74.3°	23.5°	🌤️ Comfortable	✅ Good	Jun 4
21	Kankakee River Near Wilmington, Il River	74.3°	23.5°	🌤️ Comfortable	✅ Good	Jun 4
22	Kankakee R At Inflow Of Power Plant Nr Lorenzo, Il Lake	74.1°	23.4°	🌤️ Comfortable	✅ Good	Jun 4
23	Long Lake At Ben Dock At Long Lake, Il Lake	74.1°	23.4°	🌤️ Comfortable	✅ Good	Jun 4
24	Fox River Near Mchenry, Il River	73.4°	23°	🌤️ Comfortable	✅ Good	Jun 4
25	Kaskaskia River At New Athens, Il River	73.4°	23°	🌤️ Comfortable	✅ Good	Oct 5
26	Vermilion River At Pontiac, Il River	73.2°	22.9°	🌤️ Comfortable	✅ Good	Aug 26
27	Salt Creek Near Farmer City, Il River	72.7°	22.6°	🌤️ Comfortable	✅ Good	Jun 4
28	Spoon River At Duncan Mills, Il River	72.7°	22.6°	🌤️ Comfortable	✅ Good	Aug 26
29	Rock River At Byron, Il River	72.7°	22.6°	🌤️ Comfortable	✅ Good	Jun 4
30	Spoon River At London Mills, Il River	72.5°	22.5°	🌤️ Comfortable	✅ Good	Aug 25
31	Ohio River At Olmsted, Il River	72.3°	22.4°	🌤️ Comfortable	✅ Good	Jun 4
32	Des Plaines River At Rockdale, Il River	71.8°	22.1°	🌤️ Comfortable	⚠️ Brisk	Jun 4
33	Des Plaines River At Route 53 At Joliet, Il River	71.4°	21.9°	🌤️ Comfortable	⚠️ Brisk	Jun 4
34	Vermilion River At Rte 23 Near Cornell, Il River	70.9°	21.6°	🌤️ Comfortable	⚠️ Brisk	Aug 26
35	Sugar Creek Near Chatham, Il River	70.7°	21.5°	🌤️ Comfortable	⚠️ Brisk	Jun 3
36	Vermilion River At Hwy 6 Near Mcdowell, Il River	70.5°	21.4°	🌤️ Comfortable	⚠️ Brisk	Aug 26
37	Chicago Sanitary And Ship Canal At Romeoville, Il River	70.3°	21.3°	🌤️ Comfortable	⚠️ Brisk	Jun 4
38	North Fork Vermilion River Near Charlotte, Il River	70.3°	21.3°	🌤️ Comfortable	⚠️ Brisk	Aug 26
39	Lick Creek Near Woodside, Il River	70°	21.1°	🌤️ Comfortable	⚠️ Brisk	Jun 3
40	North Fork Salt Creek Near De Witt, Il River	68.5°	20.3°	🌤️ Comfortable	⚠️ Brisk	Jun 4
41	Kickapoo Creek Near Bloomington, Il River	68.2°	20.1°	🌤️ Comfortable	⚠️ Brisk	Jul 14
42	Lake Michigan At Jackson Park At Hyde Park, Il Lake	67.8°	19.9°	🌤️ Comfortable	⚠️ Brisk	Sep 3
43	Chicago S & S Canal At Western Ave At Chicago, Il River	67.6°	19.8°	🌤️ Comfortable	⚠️ Brisk	Jun 4
44	South Fork Vermilion River At Forrest, Il River	66.7°	19.3°	🌤️ Comfortable	⚠️ Brisk	Aug 26
45	Mason Tazewell Drainage D At Cr2350E Nr Topeka, Il Lake	66.2°	19°	🌤️ Comfortable	⚠️ Brisk	Jun 5
46	Des Plaines River In Lock Channel At Rockdale, Il River	65.8°	18.8°	🌤️ Comfortable	⚠️ Brisk	Oct 14
47	Vermilion River Near Danville, Il River	65.5°	18.6°	🌤️ Comfortable	⚠️ Brisk	Oct 3
48	Kaskaskia River Near Venedy Station, Il River	65.3°	18.5°	🌤️ Comfortable	⚠️ Brisk	Sep 29
49	Illinois River Above Rte 150 At Peoria, Il River	63.3°	17.4°	🌊 Cool	🚫 Cold	Apr 30
50	Embarras River At Lawrenceville, Il River	62.1°	16.7°	🌊 Cool	🚫 Cold	Oct 18
51	Green River Near Geneseo, Il River	57°	13.9°	🌊 Cool	🚫 Cold	Oct 19
52	Spoon River At Seville, Il River	55.9°	13.3°	🌊 Cool	🚫 Cold	Oct 16
53	Illinois River At Seneca, Il River	53.4°	11.9°	❄️ Cold	⛔ Very cold	Apr 14
54	Fox River At Yorkville, Il River	48.6°	9.2°	❄️ Cold	⛔ Very cold	Nov 14
55	Mackinaw River Near Congerville, Il River	46.9°	8.3°	❄️ Cold	⛔ Very cold	Nov 18
56	Rock River Near Joslin, Il River	33.8°	1°	🧊 Very Cold	⛔ Very cold	Dec 17
57	Spring Creek At Springfield, Il River	—	—	—	—	—
58	East Branch Dupage River At Short St At Lisle, Il River	—	—	—	—	—
59	Little Kickapoo Creek Near Heyworth, Il River	—	—	—	—	—
60	Kickapoo Creek Near Kickapoo, Il River	—	—	—	—	—
61	Iroquois River At Iroquois, Il River	—	—	—	—	—
62	Illinois River At Valley City, Il River	—	—	—	—	—
63	Buffalo Creek Near Wheeling, Il River	—	—	—	—	—
64	Kaskaskia River Below Ficklin, Il River	—	—	—	—	—
65	Lake Michigan At Chicago Lock At Chicago, Il Lake	—	—	—	—	—
66	Salt Creek At Elk Grove Village, Il River	—	—	—	—	—
67	Ferson Creek Near St. Charles, Il River	—	—	—	—	—
68	Kaskaskia River Near Cowden, Il River	—	—	—	—	—
69	Boneyard Creek At Urbana, Il River	—	—	—	—	—
70	Flag Creek Near Willow Springs, Il River	—	—	—	—	—
71	Blackberry Creek Near Yorkville, Il River	—	—	—	—	—
72	Shoal Creek Near Pierron, Il River	—	—	—	—	—
73	North Fork Embarras River Near Oblong, Il River	—	—	—	—	—
74	North Branch Chicago River At Niles, Il River	—	—	—	—	—
75	Farm Creek At Farmdale, Il River	—	—	—	—	—
76	Richland Creek Near Hecker, Il River	—	—	—	—	—
77	Thorn Creek At Glenwood, Il River	—	—	—	—	—
78	Mason Tazewell Drainage D Nr Nursery Nr Topeka, Il Lake	—	—	—	—	—
79	Mississippi River At Thebes, Il River	—	—	—	—	—
80	Pecatonica River At Freeport, Il River	—	—	—	—	—
81	Natalie Creek At Midlothian, Il River	—	—	—	—	—
82	South Branch Kishwaukee River At Dekalb, Il River	—	—	—	—	—
83	Rock River Above Sinnissippi Dam At Rock Falls, Il River	—	—	—	—	—
84	West Branch Du Page River Near Naperville, Il River	—	—	—	—	—
85	Henderson Creek Near Oquawka, Il River	—	—	—	—	—
86	Aux Sable Creek Near Morris, Il River	—	—	—	—	—
87	La Moine River At Colmar, Il River	—	—	—	—	—
88	Big Creek Near Wetaug, Il River	—	—	—	—	—
89	Mill Creek At Old Mill Creek, Il River	—	—	—	—	—
90	Fox River At Johnsburg, Il River	—	—	—	—	—
91	Cahokia Creek At Edwardsville, Il River	—	—	—	—	—
92	Des Plaines River At River Forest, Il River	—	—	—	—	—
93	Poplar Creek At Elgin, Il River	—	—	—	—	—
94	West Okaw River Near Lovington, Il River	—	—	—	—	—
95	Spoon River Near St. Joseph, Il River	—	—	—	—	—
96	Addison Creek At Bellwood, Il River	—	—	—	—	—
97	Fox River Tailwater At Yorkville, Il River	—	—	—	—	—
98	Kaskaskia River At Carlyle, Il River	—	—	—	—	—
99	Black Slough At Cr 500N Nr Philo, Il Lake	—	—	—	—	—
100	Skokie River Near Highland Park, Il River	—	—	—	—	—

Sugar Creek Near Springfield, Il River

84.4°F

☀️ Warm

Sangamon River Near Oakford, Il River

82.2°F

☀️ Warm

Salt Creek Near Greenview, Il River

81.9°F

☀️ Warm

Little Wabash River At Main St At Carmi, Il River

81.7°F

☀️ Warm

Sangamon River At Fisher, Il River

81°F

☀️ Warm

Sangamon River At Monticello, Il River

80.1°F

☀️ Warm

Salt Creek Near Rowell, Il River

79.7°F

☀️ Warm

Vermilion River Near Leonore, Il River

79.3°F

☀️ Warm

Big Muddy River At Rte 127 At Murphysboro, Il River

78.8°F

☀️ Warm

Sangamon River At Petersburg, Il River

78.1°F

☀️ Warm

Calumet Sag Channel At Blue Island, Il Lake

77.9°F

☀️ Warm

Illinois River At Florence, Il River

77.5°F

☀️ Warm

South Fork Sangamon River Near Rochester, Il River

77.2°F

☀️ Warm

Mackinaw River Near Green Valley, Il River

77°F

☀️ Warm

Sangamon River At Route 48 At Decatur, Il River

75.9°F

☀️ Warm

Hanson Gravel Pit At Culvert Near Morris, Il Lake

75.6°F

☀️ Warm

Des Plaines River At Channahon, Il River

75.4°F

☀️ Warm

Mississippi River At Dam 13 Near Fulton, Il River

75.4°F

☀️ Warm

Illinois River At Starved Rock, Il River

74.8°F

🌤️ Comfortable

Kankakee River At Custer Park, Il River

74.3°F

🌤️ Comfortable

More Illinois Resources

🗺️ Illinois Water Levels 🎣 Weekly Fishing Report ⛵ Boat Ramp Status 🌵 Drought Conditions 🌡️ All States

❓ Illinois Water Temperature FAQ

What is the warmest lake in Illinois today?

Based on our latest USGS data, Sugar Creek Near Springfield, Il is currently the warmest water body in Illinois at 84.4°F.

Which Illinois lakes are good for swimming right now?

Lakes with water temperatures above 72°F are generally comfortable for swimming. Currently, Illinois's average water temperature is 70.8°F — check individual lakes above for specific conditions.

What is the best water temperature for fishing in Illinois?

The optimal temperature range depends on your target species. For bass fishing, look for water bodies between 65–75°F. For trout, target the coldest water bodies in Illinois — typically 50–65°F. Use the table above to identify which lakes are in the ideal range for your target species.

🔬 Data Methodology & Sources

Water temperature readings on this site are collected from USGS (United States Geological Survey) monitoring stations installed at lakes, rivers, and reservoirs across the country. Sensors measure water surface temperature in Celsius, which is converted to Fahrenheit for display. Data is retrieved and stored daily. Temperatures shown reflect the most recent available sensor reading for each water body, typically from the past 1–30 days depending on station reporting frequency.

⚠️ Water temperatures can vary significantly across a water body due to depth, currents, and time of day. Sensor readings represent conditions at the monitoring station location. Always exercise caution when swimming and consult local authorities for official safety advisories.