Mark Twain Lake — Current Water Temperature, Annual Trends and Forecast
This page provides information on the current water temperature in Mark Twain Lake, trends, monthly ranges and the forecast for the coming days.
Current Water Temperature
Water Temperature in Mark Twain Lake today is 22.4°C.
Water Temperature: Daily Trends, Historical Records, and Forecast
✅ As of today, the minimum water temperature ranges from 68°F (20°C) to 74°F (23°C). The water is warm and pleasant for swimming, and in this range, one can stay in the water for extended periods without the risk of hypothermia. This is the ideal temperature for relaxation, swimming, and water sports. Families with children, as well as outdoor enthusiasts, will enjoy swimming and time spent in the water. For most people, this is the optimal temperature for a comfortable beach experience. 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 |
|---|---|---|---|
| SEP 14 | 23.1°C | 25.0°C | |
| SEP 15 | 22.6°C | 25.0°C | |
| SEP 16 | 21.5°C | 25.0°C | |
| SEP 17 | 22.5°C | 25.0°C | |
| SEP 18 | 21.9°C | 25.0°C | |
| SEP 19 | 21.6°C | 25.0°C | |
| SEP 20 | 21.9°C | 25.0°C | |
| SEP 22 | 25.0°C | 22.5°C | |
| SEP 23 | 25.0°C | 22.7°C | |
| SEP 24 | 25.0°C | 22.8°C | |
| SEP 25 | 25.0°C | 22.9°C | |
| SEP 26 | 25.0°C | 23.1°C | |
| SEP 27 | 25.0°C | 23.2°C | |
| SEP 28 | 25.0°C | 23.3°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 | 3°C | 6°C |
| February | 0°C | 4°C | 7°C |
| March | 2°C | 7°C | 13°C |
| April | 7°C | 13°C | 19°C |
| May | 14°C | 19°C | 25°C |
| June | 19°C | 23°C | 26°C |
| July | 25°C | 28°C | 31°C |
| August | 24°C | 27°C | 31°C |
| September | 22°C | 25°C | 28°C |
| October | 14°C | 19°C | 23°C |
| November | 6°C | 11°C | 15°C |
| December | 2°C | 5°C | 8°C |
Mark Twain Lake: Water Temperature by Location
Mark Twain Lake: Weather Forecast
September 21
September 22
September 23
September 24
September 25
Location & Local Information
Mark Twain Lake, a reservoir in northeastern Missouri, experiences a wide range of surface water temperatures through the year. In winter the surface commonly falls to roughly 35–45°F (2–7°C), while spring warming typically brings temperatures into the 45–65°F (7–18°C) band. Summer months are warmest, with surface readings often in the 70–85°F (21–29°C) range and occasionally a few degrees higher during heat waves. In autumn the lake cools again to roughly 55–70°F (13–21°C). These are general seasonal ranges; actual temperatures vary day to day with air temperature, wind, recent rainfall and how deep the water column is, since deeper layers remain noticeably cooler than the surface.
Swimming is permitted at Mark Twain Lake but generally only in designated recreational areas and beaches managed by park authorities and the U.S. Army Corps of Engineers. Permission exists because the reservoir is managed for multi‑use recreation, yet swimmers should heed posted rules and warnings. Hazards include cold water shock early and late in the year, sudden temperature changes with depth, boat traffic, and underwater debris, and many public swim areas do not have lifeguards. Visitors should check local signage and seasonal advisories before entering the water and choose supervised or clearly marked swimming spots for safety.