Newton Lake — Current Water Temperature, Annual Trends and Forecast
This page provides information on the current water temperature in Newton Lake, trends, monthly ranges and the forecast for the coming days.
Current Water Temperature
Water Temperature in Newton Lake today is 19.7°C.
Water Temperature: Daily Trends, Historical Records, and Forecast
⚠️ As of today, the minimum water temperature ranges from 65°F (18°C) to 68°F (20°C). This is already quite warm water, which is ideal for most people. Swimming becomes comfortable, and prolonged stays in the water do not cause discomfort. This temperature is perfect for family trips and for those who prefer warmer water. It is also comfortable for water sports such as surfing or swimming. 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 5 | 21.6°C | 20.0°C | |
| OCT 6 | 21.5°C | 20.0°C | |
| OCT 7 | 20.9°C | 20.0°C | |
| OCT 8 | 20.4°C | 20.0°C | |
| OCT 9 | 20.8°C | 20.0°C | |
| OCT 10 | 20.7°C | 20.0°C | |
| OCT 11 | 20.1°C | 20.0°C | |
| OCT 12 | 20.3°C | 20.0°C | |
| OCT 13 | 20.0°C | 19.7°C | |
| OCT 14 | 20.0°C | 19.7°C | |
| OCT 15 | 20.0°C | 19.7°C | |
| OCT 16 | 20.0°C | 19.8°C | |
| OCT 17 | 20.0°C | 19.8°C | |
| OCT 18 | 20.0°C | 19.8°C | |
| OCT 19 | 20.0°C | 19.8°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 | 1°C | 6°C | 9°C |
| February | 1°C | 4°C | 6°C |
| March | 0°C | 7°C | 14°C |
| April | 9°C | 14°C | 19°C |
| May | 15°C | 19°C | 23°C |
| June | 20°C | 24°C | 27°C |
| July | 25°C | 28°C | 31°C |
| August | 20°C | 24°C | 29°C |
| September | 23°C | 27°C | 30°C |
| October | 16°C | 20°C | 24°C |
| November | 7°C | 12°C | 16°C |
| December | 2°C | 5°C | 8°C |
Newton Lake: Water Temperature by Location
Newton Lake: Weather Forecast
October 13
October 14
October 15
October 16
October 17
October 18
Location & Local Information
Newton Lake, in Jasper County, Illinois, experiences the broad seasonal swings typical of inland Midwestern reservoirs. Winter surface temperatures commonly approach freezing, roughly 34–40°F (1–4°C), while spring sees a steady rise into the 40–60°F (4–15°C) range as the water stratifies. In summer, surface waters often warm to about 70–85°F (21–29°C), with the warmest readings late in the season; deeper layers remain noticeably cooler. During autumn the lake cools back down, with surface temperatures typically falling into the 50–65°F (10–18°C) bracket as turnover begins. Local conditions — recent air temperatures, rainfall, and any inflows or thermal discharges — can push readings outside these bands on particular days.
Swimming at Newton Lake is generally not promoted because the site is managed primarily for fishing, wildlife habitat and other uses rather than as a designated beach. There are no formally maintained swim facilities, and safety concerns such as variable water quality, submerged hazards, boat traffic and potential thermal or discharge influences make unmanaged swimming inadvisable. Visitors planning to enter the water should check current site rules and signage and consider alternative public beaches in the region that provide lifeguards and official swimming infrastructure.