What is the average water temperature in Illinois?

The current average water temperature across Illinois's monitored water bodies is 73.2°F.

🌡️

Illinois Water Temperatures

Q: What is the warmest lake in Illinois today?

Ohio River At Olmsted, Il at 84.7°F.

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

With Data

73.2°F

State Avg

84.7°F

Warmest

84.7°F

Warmest

Ohio River At Olmsted, Il

73.2°F

State Average

100 water bodies

33.8°F

Coldest

Rock River Near Joslin, Il

🏊

Swimming Conditions

✅ Good for swimming

Based on avg 73.2°F

🎣

Fishing Conditions

🎣 Peak — bass, crappie, catfish

Based on avg 73.2°F

Illinois — Ranked by Temperature

59 with data

#	Water Body	°F	°C	Condition	🏊	Date
1	Ohio River At Olmsted, Il River	84.7°	29.3°	☀️ Warm	🏊 Excellent	Jul 26
2	Sugar Creek Near Springfield, Il River	84.4°	29.1°	☀️ Warm	🏊 Excellent	Jul 16
3	Big Muddy River At Rte 127 At Murphysboro, Il River	82.8°	28.2°	☀️ Warm	🏊 Excellent	Jul 27
4	Mississippi River At Dam 13 Near Fulton, Il River	82.2°	27.9°	☀️ Warm	🏊 Excellent	Jul 27
5	Sangamon River Near Oakford, Il River	82.2°	27.9°	☀️ Warm	🏊 Excellent	Jul 16
6	Salt Creek Near Greenview, Il River	81.9°	27.7°	☀️ Warm	🏊 Excellent	Jul 16
7	Illinois River At Florence, Il River	81.7°	27.6°	☀️ Warm	🏊 Excellent	Jul 27
8	Little Wabash River At Main St At Carmi, Il River	81.7°	27.6°	☀️ Warm	🏊 Excellent	Jul 17
9	Hanson Gravel Pit At Culvert Near Morris, Il Lake	81.3°	27.4°	☀️ Warm	🏊 Excellent	Jul 27
10	Sangamon River At Fisher, Il River	81°	27.2°	☀️ Warm	🏊 Excellent	Jul 15
11	Long Lake At Ben Dock At Long Lake, Il Lake	80.8°	27.1°	☀️ Warm	🏊 Excellent	Jun 30
12	Illinois River At Starved Rock, Il River	80.6°	27°	☀️ Warm	🏊 Excellent	Jul 27
13	Sangamon River At Monticello, Il River	80.1°	26.7°	☀️ Warm	🏊 Excellent	Jul 17
14	Salt Creek Near Rowell, Il River	79.7°	26.5°	☀️ Warm	✅ Good	Jul 15
15	Des Plaines River At Channahon, Il River	79.5°	26.4°	☀️ Warm	✅ Good	Jul 27
16	Vermilion River Near Leonore, Il River	79.3°	26.3°	☀️ Warm	✅ Good	Jul 11
17	Spoon River At London Mills, Il River	78.8°	26°	☀️ Warm	✅ Good	Jul 5
18	Sangamon River At Petersburg, Il River	78.1°	25.6°	☀️ Warm	✅ Good	Jul 22
19	Calumet Sag Channel At Blue Island, Il Lake	77.9°	25.5°	☀️ Warm	✅ Good	Aug 6
20	Chicago S & S Canal At Western Ave At Chicago, Il River	77.9°	25.5°	☀️ Warm	✅ Good	Jul 27
21	Fox River Near Mchenry, Il River	77.7°	25.4°	☀️ Warm	✅ Good	Jul 27
22	Sugar Creek Near Chatham, Il River	77.5°	25.3°	☀️ Warm	✅ Good	Jul 27
23	Kankakee River Near Wilmington, Il River	77.5°	25.3°	☀️ Warm	✅ Good	Jul 27
24	Rock River At Byron, Il River	77.5°	25.3°	☀️ Warm	✅ Good	Jul 27
25	South Fork Sangamon River Near Rochester, Il River	77.2°	25.1°	☀️ Warm	✅ Good	Jul 14
26	Chicago Sanitary And Ship Canal At Romeoville, Il River	77°	25°	☀️ Warm	✅ Good	Jul 27
27	Mackinaw River Near Green Valley, Il River	77°	25°	☀️ Warm	✅ Good	Aug 5
28	Des Plaines River At Rockdale, Il River	76.6°	24.8°	☀️ Warm	✅ Good	Jul 26
29	North Fork Vermilion River Near Charlotte, Il River	76.6°	24.8°	☀️ Warm	✅ Good	Jul 6
30	Kankakee River At Custer Park, Il River	76.6°	24.8°	☀️ Warm	✅ Good	Jul 26
31	Kankakee R At Inflow Of Power Plant Nr Lorenzo, Il Lake	76.5°	24.7°	☀️ Warm	✅ Good	Jul 27
32	Des Plaines River At Route 53 At Joliet, Il River	76.5°	24.7°	☀️ Warm	✅ Good	Jul 27
33	Sangamon River At Route 48 At Decatur, Il River	75.9°	24.4°	☀️ Warm	✅ Good	Jul 26
34	Spoon River Near Gilson, Il River	74.8°	23.8°	🌤️ Comfortable	✅ Good	Jul 5
35	Vermilion River At Pontiac, Il River	74.8°	23.8°	🌤️ Comfortable	✅ Good	Jul 6
36	Lick Creek Near Woodside, Il River	73.8°	23.2°	🌤️ Comfortable	✅ Good	Jul 27
37	Kaskaskia River At New Athens, Il River	73.4°	23°	🌤️ Comfortable	✅ Good	Oct 5
38	Salt Creek Near Farmer City, Il River	73°	22.8°	🌤️ Comfortable	✅ Good	Jul 27
39	Spoon River At Elmore, Il River	73°	22.8°	🌤️ Comfortable	✅ Good	Jul 6
40	Vermilion River At Hwy 6 Near Mcdowell, Il River	72.9°	22.7°	🌤️ Comfortable	✅ Good	Jul 6
41	Spoon River At Duncan Mills, Il River	72.7°	22.6°	🌤️ Comfortable	✅ Good	Aug 26
42	Mason Tazewell Drainage D At Cr2350E Nr Topeka, Il Lake	72°	22.2°	🌤️ Comfortable	✅ Good	Jul 27
43	South Fork Vermilion River At Forrest, Il River	71.6°	22°	🌤️ Comfortable	⚠️ Brisk	Jul 6
44	North Fork Salt Creek Near De Witt, Il River	71.6°	22°	🌤️ Comfortable	⚠️ Brisk	Jul 27
45	Spoon River At Modena, Il River	71.1°	21.7°	🌤️ Comfortable	⚠️ Brisk	Jul 6
46	Vermilion River At Rte 23 Near Cornell, Il River	70.9°	21.6°	🌤️ Comfortable	⚠️ Brisk	Aug 26
47	Kickapoo Creek Near Bloomington, Il River	68.2°	20.1°	🌤️ Comfortable	⚠️ Brisk	Jul 14
48	Lake Michigan At Jackson Park At Hyde Park, Il Lake	67.8°	19.9°	🌤️ Comfortable	⚠️ Brisk	Sep 3
49	Des Plaines River In Lock Channel At Rockdale, Il River	65.8°	18.8°	🌤️ Comfortable	⚠️ Brisk	Oct 14
50	Vermilion River Near Danville, Il River	65.5°	18.6°	🌤️ Comfortable	⚠️ Brisk	Oct 3
51	Kaskaskia River Near Venedy Station, Il River	65.3°	18.5°	🌤️ Comfortable	⚠️ Brisk	Sep 29
52	Illinois River Above Rte 150 At Peoria, Il River	63.3°	17.4°	🌊 Cool	🚫 Cold	Apr 30
53	Embarras River At Lawrenceville, Il River	62.1°	16.7°	🌊 Cool	🚫 Cold	Oct 18
54	Green River Near Geneseo, Il River	57°	13.9°	🌊 Cool	🚫 Cold	Oct 19
55	Spoon River At Seville, Il River	55.9°	13.3°	🌊 Cool	🚫 Cold	Oct 16
56	Illinois River At Seneca, Il River	53.4°	11.9°	❄️ Cold	⛔ Very cold	Apr 14
57	Fox River At Yorkville, Il River	48.6°	9.2°	❄️ Cold	⛔ Very cold	Nov 14
58	Mackinaw River Near Congerville, Il River	46.9°	8.3°	❄️ Cold	⛔ Very cold	Nov 18
59	Rock River Near Joslin, Il River	33.8°	1°	🧊 Very Cold	⛔ Very cold	Dec 17
60	Mill Creek At Milan, Il River	—	—	—	—	—
61	Spring Brook At 87Th Street Near Naperville, Il River	—	—	—	—	—
62	Sugar Creek Near Bloomington, Il River	—	—	—	—	—
63	Iroquois River Near Chebanse, Il River	—	—	—	—	—
64	Nippersink Creek Above Wonder Lake, Il River	—	—	—	—	—
65	Macoupin Creek Near Kane, Il River	—	—	—	—	—
66	Mc Donald Creek Near Mount Prospect, Il River	—	—	—	—	—
67	Fox River At Algonquin, Il River	—	—	—	—	—
68	Kaskaskia River At Chesterville, Il River	—	—	—	—	—
69	Fox Lake Near Lake Villa, Il Lake	—	—	—	—	—
70	Salt Creek At Elmhurst, Il River	—	—	—	—	—
71	Fox River At Montgomery, Il River	—	—	—	—	—
72	Hickory Creek Near Brownstown, Il River	—	—	—	—	—
73	Saline Branch Above 1700E Near Urbana, Il Lake	—	—	—	—	—
74	Des Plaines River Near Lemont, Il River	—	—	—	—	—
75	Indian Creek Near Fairbury, Il River	—	—	—	—	—
76	Sugar Creek Near Aviston, Il River	—	—	—	—	—
77	Wabash River At Mt. Carmel, Il River	—	—	—	—	—
78	Nb Chicago River At Grand Avenue At Chicago, Il River	—	—	—	—	—
79	Money Creek Near Towanda, Il River	—	—	—	—	—
80	Rayse Creek Near Waltonville, Il River	—	—	—	—	—
81	South Fork Saline River Nr Carrier Mills, Il River	—	—	—	—	—
82	Butterfield Creek At Flossmoor, Il River	—	—	—	—	—
83	Indian Creek Near Wyoming, Il River	—	—	—	—	—
84	Rock River At Rockton, Il River	—	—	—	—	—
85	Tinley Creek Near Palos Park, Il River	—	—	—	—	—
86	Lick Creek Near Chatham, Il River	—	—	—	—	—
87	Kishwaukee River Near Perryville, Il River	—	—	—	—	—
88	West Branch Du Page River Near West Chicago, Il River	—	—	—	—	—
89	Elkhorn Creek Near Penrose, Il River	—	—	—	—	—
90	St. Joseph Creek At Route 34 At Lisle, Il River	—	—	—	—	—
91	Kankakee River At Momence, Il River	—	—	—	—	—
92	Illinois River At Morris, Il River	—	—	—	—	—
93	Illinois River At Meredosia, Il River	—	—	—	—	—
94	Des Plaines River At Lincolnshire, Il River	—	—	—	—	—
95	Fox River At Miller Bridge Near Mchenry, Il River	—	—	—	—	—
96	Copper Slough At Champaign, Il Lake	—	—	—	—	—
97	Salt Creek At Higgins Rd Nr Elk Grove Village, Il River	—	—	—	—	—
98	Fox River At South Elgin, Il (Tailwater) River	—	—	—	—	—
99	Robinson Creek Near Shelbyville, Il River	—	—	—	—	—
100	Boneyard Creek Below 6Th Street At Champaign, Il River	—	—	—	—	—

Ohio River At Olmsted, Il River

84.7°F

☀️ Warm

Sugar Creek Near Springfield, Il River

84.4°F

☀️ Warm

Big Muddy River At Rte 127 At Murphysboro, Il River

82.8°F

☀️ Warm

Mississippi River At Dam 13 Near Fulton, Il River

82.2°F

☀️ Warm

Sangamon River Near Oakford, Il River

82.2°F

☀️ Warm

Salt Creek Near Greenview, Il River

81.9°F

☀️ Warm

Illinois River At Florence, Il River

81.7°F

☀️ Warm

Little Wabash River At Main St At Carmi, Il River

81.7°F

☀️ Warm

Hanson Gravel Pit At Culvert Near Morris, Il Lake

81.3°F

☀️ Warm

Sangamon River At Fisher, Il River

81°F

☀️ Warm

Long Lake At Ben Dock At Long Lake, Il Lake

80.8°F

☀️ Warm

Illinois River At Starved Rock, Il River

80.6°F

☀️ Warm

Sangamon River At Monticello, Il River

80.1°F

☀️ Warm

Salt Creek Near Rowell, Il River

79.7°F

☀️ Warm

Des Plaines River At Channahon, Il River

79.5°F

☀️ Warm

Vermilion River Near Leonore, Il River

79.3°F

☀️ Warm

Spoon River At London Mills, 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

Chicago S & S Canal At Western Ave At Chicago, Il River

77.9°F

☀️ Warm

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, Ohio River At Olmsted, Il is currently the warmest water body in Illinois at 84.7°F.

Which Illinois lakes are good for swimming right now?

Lakes with water temperatures above 72°F are generally comfortable for swimming. Illinois averages 73.2°F, making most water bodies suitable for swimming right now.

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.