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Saint John River — Current Water Temperature, Annual Trends and Forecast

This page provides information on the current water temperature in the Saint John River, trends, monthly ranges and the forecast for the coming days.

Saint John River, United States
Saint John River, United States © By Treeman, Public domain

Current Water Temperature

21.5°C
Today
21.9°C
Yesterday
22.3°C
A Week Ago
Get instant access to real-time water temperatures for this and all other locations with our iOS and Android apps.

Water Temperature in the Saint John River today is 21.5°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

From July 31 to August 31

Table of Daily Sea Temperature Data

Date Current Average Forecast
AUG 2422.3°C20.6°C
AUG 2522.3°C20.6°C
AUG 2622.3°C20.6°C
AUG 2722.0°C20.6°C
AUG 2821.9°C20.6°C
AUG 2921.9°C20.6°C
AUG 3021.9°C20.6°C
AUG 3121.6°C20.6°C
SEP 116.0°C21.2°C
SEP 216.0°C21.0°C
SEP 316.0°C20.7°C
SEP 416.0°C20.4°C
SEP 516.0°C20.1°C
SEP 616.0°C19.9°C
SEP 716.0°C19.6°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
January2°C6°C9°C
February2°C6°C9°C
March3°C7°C11°C
April3°C10°C16°C
May5°C13°C21°C
June11°C17°C22°C
July16°C20°C24°C
August17°C21°C25°C
September11°C16°C21°C
October8°C13°C17°C
November3°C8°C16°C
December3°C5°C8°C

Saint John River: Water Temperature by Location

Saint John River: Weather Forecast

September 1

° / °
overcast
rain: 1% | wind:

September 2

° / °
overcast
rain: 28% | wind:

September 3

° / °
slight rain showers
rain: 58% | wind:

September 4

° / °
slight rain showers
rain: 58% | wind:

September 5

° / °
slight rain showers
rain: 38% | wind:

Location & Local Information

Source Saint John Ponds
• location Somerset County, Maine, United States
Mouth Bay of Fundy
• location Saint John, New Brunswick, Canada
Length 673 km (418 mi)

The Saint John River, flowing through both the United States and Canada, provides a beautiful and relatively tranquil setting for outdoor activities, including swimming. The water temperature in the river varies depending on the season and location, but in the warmer months of summer, it typically ranges between 60°F to 75°F (15°C to 24°C), offering comfortable swimming conditions. During the cooler months, the temperature can drop significantly, especially in the northern sections of the river near New Brunswick, making swimming less inviting.

Swimming opportunities along the Saint John River are available in various regions, particularly near cities like Fredericton and Saint John in Canada, as well as the areas closer to the U.S. border. In these places, locals and visitors alike enjoy the river's calm stretches, which make it suitable for swimming. While the water is generally clean and safe, swimmers should be cautious of the river's varying currents, especially near the dam areas and after heavy rainfall. Overall, the Saint John River, with its scenic views and moderate water temperatures during the summer, is a popular spot for swimming and other water-based activities, offering a peaceful experience in nature.

Frequently Asked Questions

What is the current water temperature in the Saint John River?
Water Temperature in the Saint John River today is 21.5°C.
What is the water temperature in the Saint John River during the summer months?
The water temperature in the Saint John River in summer fluctuates in the range of 11°C - 25°C.
Is it possible to swim in the Saint John River?
Yes, it is possible to swim in the Saint John River. However, it's essential to consider water safety rules and local guidelines regarding water quality and currents.