First Connecticut Lake — Current Water Temperature, Annual Trends and Forecast
This page provides information on the current water temperature in First Connecticut Lake, trends, monthly ranges and the forecast for the coming days.
Current Water Temperature
Water Temperature in First Connecticut Lake today is 19.5°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 |
|---|---|---|---|
| AUG 24 | 20.8°C | 21.0°C | |
| AUG 25 | 20.8°C | 21.0°C | |
| AUG 26 | 20.8°C | 21.0°C | |
| AUG 27 | 20.2°C | 21.0°C | |
| AUG 28 | 20.2°C | 21.0°C | |
| AUG 29 | 20.2°C | 21.0°C | |
| AUG 30 | 20.2°C | 21.0°C | |
| AUG 31 | 19.5°C | 21.0°C | |
| SEP 1 | 20.5°C | 19.6°C | |
| SEP 2 | 20.5°C | 19.6°C | |
| SEP 3 | 20.5°C | 19.7°C | |
| SEP 4 | 20.5°C | 19.7°C | |
| SEP 5 | 20.5°C | 19.8°C | |
| SEP 6 | 20.5°C | 19.8°C | |
| SEP 7 | 20.5°C | 19.9°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 | 5°C |
| February | 0°C | 2°C | 5°C |
| March | 0°C | 2°C | 4°C |
| April | 0°C | 3°C | 6°C |
| May | 3°C | 7°C | 12°C |
| June | 10°C | 13°C | 17°C |
| July | 16°C | 22°C | 27°C |
| August | 18°C | 21°C | 24°C |
| September | 16°C | 21°C | 25°C |
| October | 8°C | 12°C | 16°C |
| November | 2°C | 5°C | 8°C |
| December | 1°C | 4°C | 6°C |
First Connecticut Lake: Water Temperature by Location
First Connecticut Lake: Weather Forecast
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September 3
September 4
September 5
Location & Local Information
First Connecticut Lake, the northernmost of New Hampshire’s Connecticut Lakes, tends to run cold through much of the year because of its high-latitude location and seasonal climate. Surface water temperatures in summer commonly range roughly from the upper 50s to low 70s °F (about 14–22 °C), with the warmest conditions typically occurring in July and August. In spring and fall the lake cools considerably, with surface readings often between the mid-30s and mid-50s °F (around 2–13 °C) as the water mixes and seasonal cooling or warming progresses. In winter the lake is normally at or just above freezing where open water remains and is often ice-covered, around 32–34 °F (0–1 °C).
Swimming is allowed in the lake but is relatively uncommon compared with warmer southern lakes, and there are few staffed swimming facilities or lifeguarded beaches. The main constraints are the generally cold water even in summer and the risk of hypothermia from prolonged immersion; visitors should exercise caution, enter gradually, and avoid long exposure without protective gear such as a wetsuit. Local campgrounds and boat ramps provide access for shore or water entry, but swimmers should assume minimal services and plan accordingly for safety.