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Little Grassy Lake is a reservoir located in Illinois. At around 1,200 acres (about 2 square miles), it is a mid-sized waterbody. Nearby alternatives include Devils Kitchen Lake, Kinkaid Lake, and Rend Lake. For this location, LakeRadar tracks an hourly and 7-day forecast, wind and gust outlook, and activity scores for boating, paddling, and swimming. Use the conditions and forecast on this page to decide when to go boating, fishing, or paddling at Little Grassy Lake.
Updated
Latest source update is older than expected. Use caution and check the official source.
The last automated check (Oct 9, 2:04 PM CDT) found no active alerts for this lake, but that check is older than LakeRadar's alert freshness window, so the current alert status could not be confirmed.
Confirm before heading out: official alerts for this area or weather.gov/alerts. LakeRadar scores summarize available conditions and are not a substitute for official warnings, local rules, or on-water judgment.
Overall Good (89/100) across 4 activities. Best right now: Boating (92/100).
How the score is calculated →Best excellent fishing window, averaging 94/100 across these hours. Wind 2 mph from the southeast. Dusk hours (19:00 local). Derived from the hourly forecast; official alerts are not forecast and are checked separately.
| Metric | 8p | 9p | 10p | 11p | 12a | 1a | 2a | 3a | 4a | 5a | 6a | 7a | 8a | 9a | 10a | 11a | 12p | 1p | 2p | 3p | 4p | 5p | 6p | 7p |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Temp (°F) | 86° | 85° | 83° | 80° | 72° | 69° | 67° | 66° | 65° | 66° | 64° | 63° | 62° | 62° | 61° | 61° | 60° | 61° | 63° | 67° | 69° | 70° | 70° | 70° |
| Wind (kts) | 6 | 5 | 4 | 3 | 2 | 2 | 3 | 3 | 3 | 3 | 3 | 3 | 3 | 2 | 2 | 2 | 2 | 3 | 4 | 4 | 4 | 4 | 5 | 5 |
| Direction | S | S | SE | SE | SE | SE | SE | SE | SE | SE | SE | SE | SE | SE | SE | SE | SE | E | E | SE | SE | SE | SE | SE |
| Gusts (kts) | 11 | 10 | 8 | 5 | 4 | 5 | 6 | 7 | 7 | 8 | 7 | 7 | 6 | 5 | 5 | 5 | 5 | 6 | 7 | 7 | 8 | 8 | 9 | 10 |
| Precip % | 0% | 0% | 0% | 0% | 0% | 0% | 0% | 0% | 0% | 0% | 1% | 1% | 1% | 1% | 1% | 1% | 2% | 3% | 3% | 4% | 5% | 9% | 20% | 21% |
| Time | Temp | Wind | Gusts | Precip | Cloud | Condition |
|---|---|---|---|---|---|---|
| Fri, 3 PM CDT | 86°F | 7 mph SSE (158°) | 13 mph | 0% | 12% | Sunny |
| Fri, 4 PM CDT | 85°F | 6 mph SSE (158°) | 12 mph | 0% | 11% | Sunny |
| Fri, 5 PM CDT | 83°F | 5 mph SE (135°) | 9 mph | 0% | 31% | Mostly Sunny |
| Fri, 6 PM CDT | 80°F | 3 mph SE (135°) | 6 mph | 0% | 29% | Partly Cloudy |
| Fri, 7 PM CDT | 72°F | 2 mph SE (135°) | 5 mph | 0% | 50% | Partly Cloudy |
| Fri, 8 PM CDT | 69°F | 2 mph ESE (113°) | 6 mph | 0% | 56% | Mostly Cloudy |
| Fri, 9 PM CDT | 67°F | 3 mph ESE (113°) | 7 mph | 0% | 61% | Mostly Cloudy |
| Fri, 10 PM CDT | 66°F | 3 mph ESE (113°) | 8 mph | 0% | 66% | Mostly Cloudy |
| Fri, 11 PM CDT | 65°F | 3 mph SE (135°) | 8 mph | 0% | 57% | Mostly Cloudy |
| Sat, 12 AM CDT | 66°F | 3 mph SE (135°) | 9 mph | 0% | 65% | Mostly Cloudy |
| Sat, 1 AM CDT | 64°F | 3 mph SE (135°) | 8 mph | 1% | 68% | Mostly Cloudy |
| Sat, 2 AM CDT | 63°F | 3 mph SE (135°) | 8 mph | 1% | 76% | Mostly Cloudy |
| Sat, 3 AM CDT | 62°F | 3 mph SE (135°) | 7 mph | 1% | 72% | Mostly Cloudy |
| Sat, 4 AM CDT | 62°F | 2 mph SE (135°) | 6 mph | 1% | 77% | Mostly Cloudy |
| Sat, 5 AM CDT | 61°F | 2 mph ESE (113°) | 6 mph | 1% | 77% | Mostly Cloudy |
| Sat, 6 AM CDT | 61°F | 2 mph ESE (113°) | 6 mph | 1% | 84% | Mostly Cloudy |
| Sat, 7 AM CDT | 60°F | 2 mph ESE (113°) | 6 mph | 2% | 81% | Mostly Cloudy |
| Sat, 8 AM CDT | 61°F | 3 mph E (90°) | 7 mph | 3% | 80% | Mostly Cloudy |
| Sat, 9 AM CDT | 63°F | 5 mph E (90°) | 8 mph | 3% | 91% | Cloudy |
| Sat, 10 AM CDT | 67°F | 5 mph ESE (113°) | 8 mph | 4% | 94% | Cloudy |
| Sat, 11 AM CDT | 69°F | 5 mph ESE (113°) | 9 mph | 5% | 93% | Cloudy |
| Sat, 12 PM CDT | 70°F | 5 mph SE (135°) | 9 mph | 9% | 93% | Cloudy |
| Sat, 1 PM CDT | 70°F | 6 mph ESE (113°) | 10 mph | 20% | 93% | Slight Chance Rain Showers |
| Sat, 2 PM CDT | 70°F | 6 mph ESE (113°) | 12 mph | 21% | 86% | Slight Chance Rain Showers |
| Sat, 3 PM CDT | 71°F | 7 mph E (90°) | 14 mph | 41% | 90% | Chance Rain Showers |
Official National Weather Service hourly forecast. Showing 10 of 25 hours. Wind arrows point the way the wind is blowing; the compass point and degrees show where it comes from.
| Period | Today October 9, 2026 | This Afternoon October 9, 2026 | Tonight October 9, 2026 | Saturday October 10, 2026 | Saturday Night October 10, 2026 | Sunday October 11, 2026 | Sunday Night October 11, 2026 | Columbus Day October 12, 2026 | Monday Night October 12, 2026 | Tuesday October 13, 2026 | Tuesday Night October 13, 2026 | Wednesday October 14, 2026 | Wednesday Night October 14, 2026 | Thursday October 15, 2026 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Temp (°F) | 86° | 86° | 60° | 72° | 58° | 78° | 60° | 87° | 66° | 88° | 64° | 80° | 63° | 79° |
| Wind | SSE 7 mph | SE 7 mph | SE 3 mph | E 2 to 10 mph | NNE 5 to 12 mph | NW 3 to 7 mph | SW 0 to 5 mph | SW 5 to 10 mph | SSW 9 mph | SW 8 mph | S 7 mph | SE 8 mph | SSE 7 mph | SSW 7 to 10 mph |
| Gusts | 13 mph | 13 mph | 9 mph | 20 mph | 22 mph | 13 mph | 9 mph | 18 mph | 16 mph | 15 mph | 13 mph | 13 mph | 13 mph | 17 mph |
| Precip % | 1% | 0% | 1% | 51% | 79% | 9% | 0% | 0% | 0% | 3% | 13% | 29% | 28% | 34% |
| Forecast |
No active USGS or USACE telemetry gauge is currently mapped to Little Grassy Lake. Not available from a verified source for this lake.
Nearby river temperature: 70.2°F at BIG MUDDY RIVER AT RTE 127 AT MURPHYSBORO, IL (16.1 mi away) · Oct 9, 8:00 PM UTC
Good for fishing (85/100), from 5 available inputs. Supporting this: Wind 7 mph from the south-southeast. 0% chance of precipitation. Not available from a verified source for this lake: pressure trend, water temperature. Confidence is moderate (74%) because some inputs are unavailable or older than ideal.
Excellent for boating (92/100), from 4 available inputs. Supporting this: Wind 7 mph from the south-southeast. No active official alerts for this lake. Not available from a verified source for this lake: visibility and conditions, verified water access. Confidence is moderate (84%) because some inputs are unavailable or older than ideal.
Good for sailing (88/100), from 4 available inputs. Supporting this: Wind 7 mph from the SSE is workable but not ideal. No active official alerts for this lake. Not available from a verified source for this lake: visibility. Confidence is high (88%).
Excellent for kayaking (91/100), from 5 available inputs. Supporting this: Wind 7 mph from the south-southeast. Gusts to 13 mph. Confidence is high (90%).
Water temperature is not available from a verified source for this lake. No swimming score is shown without it.
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Individual boat ramp GPS coordinates are maintained under the jurisdiction of IL Parks & Wildlife Authority. Public boaters should verify seasonal launch water levels, gate hours, and daily vehicle/vessel fees before traveling.
As a core recreational asset in IL, Little Grassy Lake draws water enthusiasts for angling, paddling, and watersports throughout the season. Its diverse shoreline features public parks, boat launches, and scenic day-use areas overseen by state and local natural resource agencies. Please respect designated no-wake zones and wildlife preservation areas.
Valid freshwater sport fishing license issued by Illinois Department of Natural Resources (IDNR) is required for anglers age 16+. Digital license on mobile is accepted.
Current motorized watercraft registration mandatory. Practice Clean, Drain & Dry protocols: drain all livewells and inspect props before launching. Life jackets required for all passengers.
Public shoreline and boating access managed by State & Local Authorities. Verify seasonal gate hours, launch fees, and parking rules before travel.
High-speed motorboating, pontoon cruising, wakeboarding, and water skiing across main channels. Target gamefish include Warmouth, Largemouth Bass, Green Sunfish, Bluegill. Morning hours typically provide optimal glassy conditions for kayak and stand-up paddleboard (SUP) touring.
Warm water temperatures, peak swimming, active watersports, and open full-service campgrounds. Highest weekly attendance; plan early arrivals on summer weekends.
Spring pre-spawn and fall feeding transitions create prime trophy angling conditions. Cooler air, lower boat traffic, and vibrant seasonal shoreline foliage.
Mild year-round outdoor climate. Uncrowded waters, active winter bass and crappie fishing, and open year-round boat launch access.
No external source rows are cited by the data currently shown on this page.
Updated
Scores are heuristics, not safety guarantees. LakeRadar scores summarize available conditions and are not a substitute for official warnings, local rules, or on-water judgment.
All telemetry for Little Grassy Lake is synchronized directly from authorized federal and state monitoring networks (USGS, NWS, NOAA, and state environmental authorities). Observations are strictly instrumented readings — unmonitored sensors are transparently disclosed rather than synthetic estimates.
Last source audit: Oct 9, 3:55 PM CDT