Delta Reservoir — Current Water Temperature, Annual Trends and Forecast
This page provides information on the current water temperature in Delta Reservoir, trends, monthly ranges and the forecast for the coming days.
Current Water Temperature
Water Temperature in Delta Reservoir today is 18.4°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 3 | 16.5°C | 17.2°C | |
| JUN 4 | 16.5°C | 17.2°C | |
| JUN 5 | 17.0°C | 17.2°C | |
| JUN 6 | 17.2°C | 17.2°C | |
| JUN 7 | 17.6°C | 17.2°C | |
| JUN 8 | 17.9°C | 17.2°C | |
| JUN 10 | 18.4°C | 17.2°C | |
| JUN 11 | 17.2°C | 18.3°C | |
| JUN 12 | 17.2°C | 18.3°C | |
| JUN 13 | 17.2°C | 18.2°C | |
| JUN 14 | 17.2°C | 18.2°C | |
| JUN 15 | 17.2°C | 18.1°C | |
| JUN 16 | 17.2°C | 18.0°C | |
| JUN 17 | 17.2°C | 18.0°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 | 3°C | 5°C |
| February | 0°C | 2°C | 5°C |
| March | 0°C | 3°C | 6°C |
| April | 3°C | 8°C | 12°C |
| May | 9°C | 13°C | 17°C |
| June | 15°C | 17°C | 20°C |
| July | 20°C | 25°C | 29°C |
| August | 20°C | 23°C | 25°C |
| September | 16°C | 19°C | 22°C |
| October | 13°C | 15°C | 17°C |
| November | 4°C | 9°C | 13°C |
| December | 2°C | 5°C | 7°C |
Delta Reservoir: Water Temperature by Location
Delta Reservoir: Weather Forecast
June 9
June 10
June 11
June 12
Location & Local Information
Delta Reservoir (often called Delta Lake) in upstate New York experiences marked seasonal variation in water temperature typical of inland reservoirs. In summer the surface can warm into the mid-60s to mid-70s °F (about 18–24 °C) on warm, calm days, while deeper water and shaded bays commonly remain much cooler in the 50s °F (10–15 °C). Spring and fall see a broad band from the upper 30s to mid-50s °F (3–13 °C) as the water transitions, and in winter surface temperatures approach freezing, around 32–40 °F (0–4 °C), with ice forming in sustained cold periods. Sudden thermal stratification and cold pockets are common, so surface readings can be misleading compared with temperatures a few feet down.
Swimming at Delta Reservoir is subject to local park rules and practical safety considerations rather than being universally promoted. Many reservoirs restrict or discourage open swimming because of cold-water shock risk, submerged hazards, variable currents, and boat traffic; lifeguards are often not provided. Where the state park or managing agency designates a supervised or signed swimming area, it may be used in warmer months, but otherwise entry into the water is typically discouraged for safety and water-quality reasons. Visitors should heed posted regulations and warnings before entering the water.