Three Mile Reservoir — Current Water Temperature, Annual Trends and Forecast
This page provides information on the current water temperature in Three Mile Reservoir, trends, monthly ranges and the forecast for the coming days.
Current Water Temperature
Water Temperature in Three Mile Reservoir today is 28.6°C.
Water Temperature: Daily Trends, Historical Records, and Forecast
✅ As of today, the minimum water temperature is above 82°F (28°C). This is very warm water, which may feel almost hot to most people. Swimming in such conditions is perfect for those seeking relaxation and comfort in the water. These waters are often preferred for relaxation in hot weather, as the water temperature does not cool the body significantly. However, it is important to remember that in such warm waters, caution is necessary, as prolonged exposure without rest can lead to overheating. 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 |
|---|---|---|---|
| AUG 4 | 29.0°C | 27.0°C | |
| AUG 5 | 29.2°C | 27.0°C | |
| AUG 6 | 29.2°C | 27.0°C | |
| AUG 7 | 28.9°C | 27.0°C | |
| AUG 8 | 28.5°C | 27.0°C | |
| AUG 9 | 28.5°C | 27.0°C | |
| AUG 10 | 28.2°C | 27.0°C | |
| AUG 11 | 28.4°C | 27.0°C | |
| AUG 12 | 27.0°C | 28.5°C | |
| AUG 13 | 27.0°C | 28.4°C | |
| AUG 14 | 27.0°C | 28.4°C | |
| AUG 15 | 27.0°C | 28.3°C | |
| AUG 16 | 27.0°C | 28.2°C | |
| AUG 17 | 27.0°C | 28.1°C | |
| AUG 18 | 27.0°C | 28.0°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 | 1°C | 4°C |
| February | 0°C | 1°C | 4°C |
| March | 0°C | 5°C | 11°C |
| April | 7°C | 12°C | 17°C |
| May | 13°C | 17°C | 22°C |
| June | 19°C | 22°C | 25°C |
| July | 23°C | 29°C | 34°C |
| August | 24°C | 27°C | 30°C |
| September | 21°C | 24°C | 27°C |
| October | 13°C | 18°C | 22°C |
| November | 4°C | 9°C | 14°C |
| December | 1°C | 3°C | 6°C |
Three Mile Reservoir: Water Temperature by Location
Three Mile Reservoir: Weather Forecast
August 12
August 13
August 14
August 15
August 16
Location & Local Information
Three Mile Reservoir in Iowa typically follows the seasonal temperature patterns of midwestern shallow reservoirs. Surface water in the coldest months often sits near freezing, around 32–40°F (0–4°C) when ice is present or forming. In spring the surface warms from roughly 40–60°F (4–16°C) as runoff and air temperatures rise. By summer, surface temperatures most commonly range from about 70–80°F (21–27°C), with shallow bays occasionally reaching the low 80s°F (27–29°C) on hot, calm days; deeper water remains cooler. In autumn the water cools back through the 60s to 50s°F (16–10°C). These are typical surface ranges; readings vary with depth, weather, wind, and recent precipitation, and a thermocline can develop in deeper areas that keeps bottom waters noticeably cooler.
Swimming at Three Mile Reservoir is generally possible but depends on local management, posted rules, and current water quality and safety conditions. Many reservoirs allow public swimming in designated areas, but there may be no lifeguards, and algae blooms, bacterial advisories, or boating traffic can lead to temporary restrictions. Visitors should check local signs or contact reservoir authorities before entering the water, pay attention to seasonal hazards like cold shock in spring and submerged hazards near shore, and use caution in areas without lifeguard supervision.