Mansfield Hollow Lake — Current Water Temperature, Annual Trends and Forecast
This page provides information on the current water temperature in Mansfield Hollow Lake, trends, monthly ranges and the forecast for the coming days.
Current Water Temperature
Water Temperature in Mansfield Hollow Lake today is 20°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 |
|---|---|---|---|
| SEP 14 | 21.5°C | 23.9°C | |
| SEP 15 | 21.4°C | 23.9°C | |
| SEP 16 | 20.8°C | 23.9°C | |
| SEP 17 | 19.8°C | 23.9°C | |
| SEP 18 | 19.5°C | 23.9°C | |
| SEP 19 | 20.4°C | 23.9°C | |
| SEP 20 | 21.1°C | 23.9°C | |
| SEP 21 | 20.4°C | 23.9°C | |
| SEP 22 | 23.9°C | 20.2°C | |
| SEP 23 | 23.9°C | 20.4°C | |
| SEP 24 | 23.9°C | 20.6°C | |
| SEP 25 | 23.9°C | 20.8°C | |
| SEP 26 | 23.9°C | 21.0°C | |
| SEP 27 | 23.9°C | 21.2°C | |
| SEP 28 | 23.9°C | 21.4°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 | 2°C | 5°C | 8°C |
| March | 3°C | 7°C | 10°C |
| April | 6°C | 10°C | 14°C |
| May | 11°C | 15°C | 20°C |
| June | 15°C | 19°C | 23°C |
| July | 21°C | 26°C | 31°C |
| August | 23°C | 26°C | 28°C |
| September | 21°C | 24°C | 27°C |
| October | 13°C | 18°C | 22°C |
| November | 6°C | 11°C | 14°C |
| December | 1°C | 4°C | 8°C |
Mansfield Hollow Lake: Water Temperature by Location
Mansfield Hollow Lake: Weather Forecast
September 21
September 22
September 23
September 24
September 25
September 26
Location & Local Information
Mansfield Hollow Lake, a reservoir in northeastern Connecticut within Mansfield Hollow State Park, experiences the full range of New England seasonal water temperatures. In winter the surface can be near freezing, roughly 32–40°F (0–4°C), with ice common; spring warms into the 40–60°F range (4–16°C) as runoff and air temperatures rise. By midsummer surface temperatures often reach the mid‑60s to upper‑70s Fahrenheit, about 65–80°F (18–27°C) in typical warm years, while autumn sees cooling back to roughly 45–60°F (7–16°C). Depth, shading, and inflows create variability, so deeper spots stay colder than shallow sheltered coves.
Swimming is permitted in association with the state park’s recreational areas, but access and conditions are managed for safety and environmental reasons. There are designated swim areas during the warmer months when park staff deem conditions appropriate; however lifeguards are not always present and boat traffic, reservoir currents from flow management, water quality advisories, and weather can restrict or make swimming unsafe at times. Visitors should follow posted rules, be aware that temperatures can feel brisk below the surface even in summer, and exercise caution when entering the water.