Rondout Reservoir — Current Water Temperature, Annual Trends and Forecast
This page provides information on the current water temperature in Rondout Reservoir, trends, monthly ranges and the forecast for the coming days.
Current Water Temperature
Water Temperature in Rondout Reservoir today is 18.1°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 |
|---|---|---|---|
| JUN 23 | 18.9°C | 17.0°C | |
| JUN 24 | 18.9°C | 17.0°C | |
| JUN 25 | 18.8°C | 17.0°C | |
| JUN 26 | 19.1°C | 17.0°C | |
| JUN 27 | 19.2°C | 17.0°C | |
| JUN 28 | 18.1°C | 17.0°C | |
| JUN 29 | 18.2°C | 17.0°C | |
| JUN 30 | 17.9°C | 17.0°C | |
| JUL 1 | 21.5°C | 18.3°C | |
| JUL 2 | 21.5°C | 18.4°C | |
| JUL 3 | 21.5°C | 18.6°C | |
| JUL 4 | 21.5°C | 18.8°C | |
| JUL 5 | 21.5°C | 19.0°C | |
| JUL 6 | 21.5°C | 19.1°C | |
| JUL 7 | 21.5°C | 19.3°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 | 2°C | 5°C |
| February | 0°C | 1°C | 4°C |
| March | 0°C | 3°C | 7°C |
| April | 4°C | 8°C | 13°C |
| May | 9°C | 13°C | 17°C |
| June | 12°C | 17°C | 22°C |
| July | 13°C | 22°C | 30°C |
| August | 17°C | 23°C | 29°C |
| September | 15°C | 21°C | 27°C |
| October | 9°C | 13°C | 17°C |
| November | 5°C | 9°C | 12°C |
| December | 1°C | 4°C | 6°C |
Rondout Reservoir: Water Temperature by Location
Rondout Reservoir: Weather Forecast
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Location & Local Information
Rondout Reservoir, part of New York City’s Catskills supply system, exhibits typical seasonal temperature shifts for a deep, inland reservoir. Surface temperatures in winter commonly hover around freezing to the low 40s °F (about 0 to 4 °C). In spring the water generally warms from roughly the mid-30s to mid-50s °F (2 to 13 °C) as air temperatures rise. By summer, surface waters most often reach the upper 60s to upper 70s °F (20 to 26 °C) and on hot, calm days can push into the low 80s °F (27 to 28 °C), while deeper layers remain markedly cooler. In autumn the reservoir cools back through the 50s and 60s °F (10 to 18 °C) before winter onset. Local weather, wind, incoming streams, and depth all influence these values and temperatures can vary from one year to the next.
Swimming in Rondout Reservoir is not permitted. As a primary component of New York City’s drinking water supply, the reservoir is subject to strict Department of Environmental Protection rules intended to protect water quality and public health; prohibiting direct human contact helps reduce contamination risk and supports reservoir management. In addition, steep banks, deep cold layers, and variable currents can make unsupervised swimming unsafe. Recreational access and permitted uses are managed by the authorities, so people seeking water recreation should look for designated swimming areas and facilities where bathing is allowed.