Wanaque Reservoir — Current Water Temperature, Annual Trends and Forecast
This page provides information on the current water temperature in Wanaque Reservoir, trends, monthly ranges and the forecast for the coming days.
Current Water Temperature
Water Temperature in Wanaque Reservoir today is 21.9°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 | 22.2°C | 22.5°C | |
| SEP 15 | 22.6°C | 22.5°C | |
| SEP 16 | 22.3°C | 22.5°C | |
| SEP 17 | 22.2°C | 22.5°C | |
| SEP 18 | 20.6°C | 22.5°C | |
| SEP 19 | 20.8°C | 22.5°C | |
| SEP 20 | 22.1°C | 22.5°C | |
| SEP 21 | 21.9°C | 22.5°C | |
| SEP 22 | 22.5°C | 21.9°C | |
| SEP 23 | 22.5°C | 22.0°C | |
| SEP 24 | 22.5°C | 22.0°C | |
| SEP 25 | 22.5°C | 22.0°C | |
| SEP 26 | 22.5°C | 22.1°C | |
| SEP 27 | 22.5°C | 22.1°C | |
| SEP 28 | 22.5°C | 22.1°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 | 4°C | 9°C |
| April | 4°C | 10°C | 16°C |
| May | 11°C | 15°C | 20°C |
| June | 17°C | 21°C | 25°C |
| July | 23°C | 27°C | 30°C |
| August | 23°C | 26°C | 29°C |
| September | 18°C | 23°C | 27°C |
| October | 12°C | 16°C | 20°C |
| November | 6°C | 9°C | 12°C |
| December | 1°C | 4°C | 7°C |
Wanaque Reservoir: Water Temperature by Location
Wanaque Reservoir: Weather Forecast
September 22
September 23
September 24
September 25
Location & Local Information
Wanaque Reservoir, a man-made impoundment in northern New Jersey that supplies drinking water to the region, typically shows seasonal surface temperatures that reflect local weather and depth. In spring, surface water commonly ranges from about 45–65°F (7–18°C) as the lake warms; summer surface temperatures most often sit between roughly 70–80°F (21–27°C), with occasional pockets reaching the low 80s°F (around 28°C) on hot, calm afternoons. By autumn the surface cools into the 50–65°F (10–18°C) band before dropping further in winter when surface readings often fall to near freezing, roughly 32–40°F (0–4°C), and portions of the reservoir can ice over. Deeper water remains noticeably colder year-round because of stratification, sometimes 10–15°F (6–8°C) below surface values, and exact temperatures vary with inflow, weather and time of day.
Swimming in Wanaque Reservoir is generally not permitted because the impoundment functions as a public drinking-water supply and is subject to restrictions for public health, safety and legal reasons. There are no formal swim beaches or lifeguarded areas, and managers cite contamination risk, cold-water and underwater hazards, and liability concerns as reasons for prohibitions and enforcement. Even in summer, sudden cold depths and boat traffic can present hazards, so recreational activities are limited or regulated rather than allowing open swimming.