Upper Peoria Lake — Current Water Temperature, Annual Trends and Forecast
This page provides information on the current water temperature in Upper Peoria Lake, trends, monthly ranges and the forecast for the coming days.
Current Water Temperature
Water Temperature in Upper Peoria Lake today is 15.4°C.
Water Temperature: Daily Trends, Historical Records, and Forecast
⚠️ As of today, the minimum water temperature ranges from 60°F (15°C) to 65°F (18°C). The water is comfortable for most people, making it an ideal range for water sports enthusiasts. The temperature does not cause significant discomfort, and swimming will be pleasant for the majority. However, it's important to remember that prolonged exposure to the water can still lead to cooling, so it's essential to monitor the time spent in the water, especially for children or elderly people. It is important to note that these swimming tips and recommendations apply only in good weather. When the air temperature is below 68°F (20°C), and sometimes even below 77°F (25°C), swimming can be unpleasant even with relatively high water temperatures.
Water Temperature Chart Over the Last 30 Days
Table of Daily Sea Temperature Data
| Date | Current | Average | Forecast |
|---|---|---|---|
| OCT 6 | 17.0°C | 18.5°C | |
| OCT 7 | 16.9°C | 18.5°C | |
| OCT 8 | 16.2°C | 18.5°C | |
| OCT 9 | 16.7°C | 18.5°C | |
| OCT 10 | 16.2°C | 18.5°C | |
| OCT 11 | 16.0°C | 18.5°C | |
| OCT 12 | 15.7°C | 18.5°C | |
| OCT 14 | 18.5°C | 15.6°C | |
| OCT 15 | 18.5°C | 15.7°C | |
| OCT 16 | 18.5°C | 15.9°C | |
| OCT 17 | 18.5°C | 16.0°C | |
| OCT 18 | 18.5°C | 16.2°C | |
| OCT 19 | 18.5°C | 16.3°C | |
| OCT 20 | 18.5°C | 16.5°C |
* Current - Actual water temperature value
** Average - Average water temperature on this day in recent years
*** Forecast - Our water temperature forecast
Actual nearshore water temperatures may fluctuate by several degrees from the reported values, especially following heavy rainfall or extended periods of strong winds. Certain wind patterns can cause colder, deeper waters to rise and replace the sun-warmed surface water, leading to noticeable variations.
Our forecast is based on a proprietary mathematical model that considers real-time water temperature changes, historical trends, key weather patterns, wind strength and direction, and air temperature specific to each region. Additionally, we incorporate data from other resorts to enhance accuracy.
Monthly Water Temperature Range (Min, Max & Average)
| Month | Min | Avg | Max |
|---|---|---|---|
| January | 0°C | 4°C | 7°C |
| February | 0°C | 3°C | 5°C |
| March | 3°C | 7°C | 11°C |
| April | 7°C | 13°C | 19°C |
| May | 14°C | 19°C | 24°C |
| June | 19°C | 23°C | 27°C |
| July | 23°C | 28°C | 33°C |
| August | 23°C | 27°C | 31°C |
| September | 21°C | 26°C | 31°C |
| October | 13°C | 19°C | 24°C |
| November | 3°C | 8°C | 13°C |
| December | 1°C | 6°C | 10°C |
Upper Peoria Lake: Water Temperature by Location
Upper Peoria Lake: Weather Forecast
October 13
October 14
October 15
October 16
October 17
Location & Local Information
Upper Peoria Lake, a broad backwater reach of the Illinois River near Peoria, shows marked seasonal variation in surface temperature. In winter the water can approach near-freezing conditions, often around 32–36°F (0–2°C) beneath ice cover or in cold spells. Spring brings steady warming, with surface readings commonly in the 45–60°F (7–16°C) range as air temperatures and river flow moderate. Summer months produce the warmest water, typically from about 70–82°F (21–28°C) on sunny afternoons, although shallow bays and sluggish backwaters can climb a few degrees higher. In autumn the lake cools again into roughly 55–68°F (13–20°C) before late-season chills set in. These are approximate surface temperatures; deeper water and shaded channels remain cooler and short-term weather shifts cause quick variation.
Swimming on Upper Peoria Lake is not generally provided with extensive lifeguarded beaches, but wading and swimming occur in accessible spots and at parks that allow it. Whether swimming is advisable or permitted depends on location and conditions: boat traffic, submerged hazards, strong currents in the riverine system, variable water quality from runoff and occasional algal blooms, and the absence of formal safety supervision can make open-water swimming risky. Local authorities and park managers may restrict access or recommend that people use designated, monitored swimming areas nearby for safety and public-health reasons.