Tappan Lake — Current Water Temperature, Annual Trends and Forecast
This page provides information on the current water temperature in Tappan Lake, trends, monthly ranges and the forecast for the coming days.
Current Water Temperature
Water Temperature in Tappan Lake today is 21.7°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 |
|---|---|---|---|
| SEP 14 | 22.6°C | 23.0°C | |
| SEP 15 | 23.4°C | 23.0°C | |
| SEP 16 | 22.7°C | 23.0°C | |
| SEP 17 | 22.1°C | 23.0°C | |
| SEP 18 | 20.5°C | 23.0°C | |
| SEP 19 | 21.3°C | 23.0°C | |
| SEP 20 | 21.5°C | 23.0°C | |
| SEP 21 | 21.7°C | 23.0°C | |
| SEP 22 | 23.0°C | 21.8°C | |
| SEP 23 | 23.0°C | 21.8°C | |
| SEP 24 | 23.0°C | 21.9°C | |
| SEP 25 | 23.0°C | 22.0°C | |
| SEP 26 | 23.0°C | 22.0°C | |
| SEP 27 | 23.0°C | 22.1°C | |
| SEP 28 | 23.0°C | 22.2°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 | 4°C | 6°C |
| February | 0°C | 4°C | 7°C |
| March | 2°C | 6°C | 10°C |
| April | 5°C | 11°C | 18°C |
| May | 12°C | 17°C | 22°C |
| June | 15°C | 20°C | 24°C |
| July | 21°C | 24°C | 28°C |
| August | 21°C | 24°C | 27°C |
| September | 20°C | 23°C | 26°C |
| October | 11°C | 17°C | 23°C |
| November | 4°C | 9°C | 13°C |
| December | 2°C | 6°C | 8°C |
Tappan Lake: Water Temperature by Location
Tappan Lake: Weather Forecast
September 21
September 22
September 23
September 24
September 25
Location & Local Information
Tappan Lake’s surface water temperatures follow the typical seasonal pattern of Ohio reservoirs, rising and falling with air temperatures and sunlight. In winter the lake commonly sits near freezing to roughly 32–40°F (0–4°C) at the surface, while spring warming brings temperatures into the 40–60°F range (4–15°C). Summer is when the warmest surface readings occur, often climbing to about 68–82°F (20–28°C) on mild to hot days, and can occasionally approach the high 80s°F (around 30°C) during heat waves in shallow, sheltered bays. Autumn sees a steady decline, with surface temperatures generally falling back into the 50–65°F band (10–18°C) as weather cools. Deeper water remains colder year-round and local conditions such as recent storms, wind, and time of day cause considerable short-term variability.
Swimming is generally possible at Tappan Lake but is best and safest in designated recreational areas during the warmer months when surface temperatures are comfortable for prolonged activity. Access and permitted activities can vary by shoreline ownership and management, and some spots may be unsuitable because of boat traffic, drop-offs, or cooler, deeper water that increases hypothermia risk. There are often no lifeguards, so swimmers should observe posted rules, be cautious of changing conditions, and avoid swimming in cold seasons when water temperatures pose a health hazard.