Lake Sebago — Current Water Temperature, Annual Trends and Forecast
This page provides information on the current water temperature in Lake Sebago, trends, monthly ranges and the forecast for the coming days.
Current Water Temperature
Water Temperature in Lake Sebago today is 20.6°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 | 21.4°C | 23.5°C | |
| SEP 15 | 21.8°C | 23.5°C | |
| SEP 16 | 21.5°C | 23.5°C | |
| SEP 17 | 20.2°C | 23.5°C | |
| SEP 18 | 20.4°C | 23.5°C | |
| SEP 19 | 20.9°C | 23.5°C | |
| SEP 20 | 20.6°C | 23.5°C | |
| SEP 21 | 20.6°C | 23.5°C | |
| SEP 22 | 23.5°C | 20.7°C | |
| SEP 23 | 23.5°C | 20.9°C | |
| SEP 24 | 23.5°C | 21.0°C | |
| SEP 25 | 23.5°C | 21.2°C | |
| SEP 26 | 23.5°C | 21.3°C | |
| SEP 27 | 23.5°C | 21.5°C | |
| SEP 28 | 23.5°C | 21.6°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 | 2°C | 5°C |
| February | 0°C | 1°C | 4°C |
| March | 0°C | 4°C | 7°C |
| April | 3°C | 9°C | 15°C |
| May | 11°C | 16°C | 21°C |
| June | 17°C | 20°C | 24°C |
| July | 21°C | 26°C | 30°C |
| August | 22°C | 26°C | 29°C |
| September | 20°C | 24°C | 27°C |
| October | 11°C | 16°C | 20°C |
| November | 6°C | 9°C | 12°C |
| December | 0°C | 4°C | 7°C |
Lake Sebago: Water Temperature by Location
Lake Sebago: Weather Forecast
September 21
September 22
September 23
September 24
September 25
September 26
Location & Local Information
Lake Sebago, a man-made lake in Harriman State Park, typically shows a wide seasonal swing in surface water temperatures. In winter the surface often approaches freezing, roughly 32–40°F (0–4°C) and can ice over on cold stretches. During spring the water gradually warms into the mid-40s to low-60s °F (about 7–16°C) as air temperatures rise and runoff mixes in. Summer brings the warmest conditions: surface readings commonly range from the low to mid 70s °F (around 21–25°C) and on hot, calm days can edge into the upper 70s °F (about 25–26°C). In fall the lake cools again, often sitting in the 50s to low 60s °F (10–16°C) as nights turn colder.
Swimming is allowed in Lake Sebago but generally only in designated beach areas during the park’s official swimming season and subject to state park rules and posted advisories. The park may staff lifeguards at busy times, but visitors should check current conditions before entering the water since temporary closures can occur for water‑quality concerns, algal blooms, or safety issues. The lake’s relatively shallow, sunlit edges warm in summer and are most comfortable for swimming, while spring and fall waters can feel brisk and winter immersion is unsafe without specialized equipment and training.