Stonington — Water Temperature, Sea Conditions & Trends
This page provides clear and up-to-date information about water temperature for Stonington (Connecticut, United States). It includes the current water temperature, daily data for the last month presented in a simple chart, and a 7-day forecast. The page also compares today’s value with typical averages for this period, shows usual monthly ranges during the year, and lists nearby beaches with short descriptions. Local weather for the next few days and general details about Stonington help you plan your visit and choose the best time for swimming.
Current Water Temperature
Water temperature in Stonington in the Atlantic Ocean today is 19°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
Water temperature in Stonington has risen over the last week and month. Currently, the sea water temperature at this location matches the average for this day in previous years.
According to our forecast, Water temperature in Stonington will be 20.1°C in the next 7 days. See the table below for daily data for the upcoming week.
Table of Daily Sea Temperature Data
| Date | Current | Average | Forecast |
|---|---|---|---|
| JUN 24 | 17.0°C | 4.8°C | |
| JUN 25 | 17.2°C | 4.8°C | |
| JUN 26 | 17.5°C | 8.8°C | |
| JUN 27 | 17.6°C | 9.0°C | |
| JUN 28 | 18.4°C | 13.3°C | |
| JUN 29 | 18.5°C | 13.3°C | |
| JUN 30 | 18.6°C | 20.0°C | |
| JUL 1 | 19.7°C | 20.0°C | |
| JUL 2 | 19.3°C | 20.0°C | 19.3°C |
| JUL 3 | 19.8°C | 19.4°C | |
| JUL 4 | 19.8°C | 19.5°C | |
| JUL 5 | 20.0°C | 19.6°C | |
| JUL 6 | 19.8°C | 19.7°C | |
| JUL 7 | 20.0°C | 19.9°C | |
| JUL 8 | 20.8°C | 20.0°C | |
| JUL 9 | 20.3°C | 20.1°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.
Water temperature data for this location is gathered from various sources, including buoys and satellite sea and ocean surface maps provided by the NOAA agency. We also incorporate data from local authorities in each specific location worldwide to ensure more accurate temperature readings.
Annual Water Temperature Overview by Month
Monthly Water Temp Ranges
Annual Water Temperature Trend
Stonington, Connecticut sits on the southeastern edge of the state where Long Island Sound and Fishers Island Sound meet, giving it a varied coastline of sandy coves, rocky points and sheltered harbors. Water temperatures around Stonington change with the seasons: in winter surface temperatures commonly range from about 0°C to 4°C, spring sees a steady rise to roughly 4°C–15°C depending on month and weather, summer brings the warmest conditions with typical values of 16°C–24°C (often peaking in July and August), and autumn cools back to roughly 10°C–18°C as the season progresses. Local conditions are influenced by tidal exchange, wind, and shallow bays, so temperatures at small coves or shallow beaches can be several degrees warmer or cooler than open-sound readings.
Monthly Water Temperature Range (Min, Max & Average)
| Month | Min | Avg | Max |
|---|---|---|---|
| January | 2°C | 5°C | 10°C |
| February | 2°C | 4°C | 7°C |
| March | 2°C | 4°C | 7°C |
| April | 3°C | 7°C | 12°C |
| May | 8°C | 12°C | 17°C |
| June | 12°C | 17°C | 23°C |
| July | 17°C | 21°C | 25°C |
| August | 19°C | 22°C | 26°C |
| September | 17°C | 20°C | 24°C |
| October | 13°C | 18°C | 21°C |
| November | 9°C | 13°C | 17°C |
| December | 5°C | 8°C | 12°C |
* Click on a month to view detailed water temperature data.
Stonington: Weather Forecast
July 3
July 4
July 5
July 6
Location, Beaches & Local Information
Nearby Beaches & Facilities
Dubois Beach
Mystic River Beach
Esker Point Beach
Noank Shipyard Inc
Fisher's Island Club
Napatree Point Conservation Area
Napatree Point
Watch Hill Beach Association Beach
Watch Hill Beach
Swimming Conditions
Swimming and beach holidays in Stonington are largely seasonal, with the main recreational window during mid-June through early September when water temperatures are most comfortable for casual bathing and longer swims. The coastline offers family-oriented sandy stretches and rockier shoreline ideal for tide pooling, while sheltered inlets provide calmer water for children and less experienced swimmers. Visitors also find opportunities for kayaking, paddleboarding and snorkeling in warmer months when visibility improves. Shoulder seasons attract open-water and cold-water swimmers who take advantage of clearer, quieter conditions but should be prepared for cooler temperatures. Facilities, lifeguard availability and access vary by beach and season, so planning around summer months will maximize warm-water swimming and beach amenities.