Charles River — Current Water Temperature, Annual Trends and Forecast
This page provides information on the current water temperature in the Charles River, trends, monthly ranges and the forecast for the coming days.
Current Water Temperature
Water Temperature in the Charles River today is 21.8°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 |
|---|---|---|---|
| AUG 24 | 21.4°C | 20.6°C | |
| AUG 25 | 21.4°C | 20.6°C | |
| AUG 26 | 21.3°C | 20.6°C | |
| AUG 27 | 21.5°C | 20.6°C | |
| AUG 28 | 21.7°C | 20.6°C | |
| AUG 29 | 21.7°C | 20.6°C | |
| AUG 30 | 21.7°C | 20.6°C | |
| AUG 31 | 21.8°C | 20.6°C | |
| SEP 1 | 16.0°C | 21.5°C | |
| SEP 2 | 16.0°C | 21.2°C | |
| SEP 3 | 16.0°C | 20.9°C | |
| SEP 4 | 16.0°C | 20.6°C | |
| SEP 5 | 16.0°C | 20.4°C | |
| SEP 6 | 16.0°C | 20.1°C | |
| SEP 7 | 16.0°C | 19.8°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 | 3°C | 4°C | 9°C |
| February | 3°C | 5°C | 9°C |
| March | 3°C | 8°C | 13°C |
| April | 5°C | 12°C | 19°C |
| May | 8°C | 13°C | 21°C |
| June | 14°C | 19°C | 22°C |
| July | 17°C | 21°C | 25°C |
| August | 17°C | 21°C | 25°C |
| September | 11°C | 16°C | 21°C |
| October | 8°C | 14°C | 19°C |
| November | 3°C | 8°C | 16°C |
| December | 3°C | 5°C | 8°C |
Charles River: Water Temperature by Location
Charles River: Weather Forecast
September 1
September 2
September 3
September 4
September 5
Location & Local Information
Source Echo Lake
• location Hopkinton, Massachusetts, United States
• elevation 350 ft (110 m)
Mouth Boston Harbor
• location Boston, Massachusetts, United States
• elevation 0 ft (0 m)
Length 80 mi (130 km)
The Charles River, flowing through eastern Massachusetts, is a historically significant and picturesque waterway stretching over 80 miles from Hopkinton to Boston Harbor. While it serves as a vital cultural and recreational hub, its water quality and suitability for swimming have been subjects of much effort and improvement over the years. Thanks to rigorous environmental initiatives, the river is now considered safe for swimming on certain days, particularly during organized events like the Charles River Swimming Club’s annual races. However, swimming is not universally permitted and depends on specific locations and water quality conditions.
Water temperature in the Charles River varies seasonally, making it most inviting during the summer months, typically ranging from 68°F to 75°F (20°C to 24°C) in July and August. These temperatures align with comfortable swimming conditions, though the experience may still depend on the day's weather and water cleanliness. Outside the summer, the river cools significantly, especially in the winter, when temperatures can drop near freezing, rendering it unsuitable for swimming. While casual swimming opportunities remain limited due to safety and environmental concerns, the Charles River remains an iconic destination for kayaking, rowing, and enjoying waterfront views.