Keystone Lake — Current Water Temperature, Annual Trends and Forecast
This page provides information on the current water temperature in Keystone Lake, trends, monthly ranges and the forecast for the coming days.
Current Water Temperature
Water Temperature in Keystone Lake today is 24.5°C.
Water Temperature: Daily Trends, Historical Records, and Forecast
✅ As of today, the minimum water temperature ranges from 75°F (23°C) to 79°F (26°C). This is a very comfortable temperature for swimming, and many people can enjoy prolonged stays in the water without feeling cold. The water is pleasantly warm, making it ideal for relaxation and water sports. This temperature range is particularly popular among tourists, as it combines comfort and safety for health. 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 |
|---|---|---|---|
| AUG 6 | 26.0°C | 25.5°C | |
| AUG 7 | 26.0°C | 25.5°C | |
| AUG 8 | 26.3°C | 25.5°C | |
| AUG 9 | 25.5°C | 25.5°C | |
| AUG 10 | 25.2°C | 25.5°C | |
| AUG 11 | 25.2°C | 25.5°C | |
| AUG 12 | 25.0°C | 25.5°C | |
| AUG 13 | 24.5°C | 25.5°C | |
| AUG 14 | 25.5°C | 24.6°C | |
| AUG 15 | 25.5°C | 24.6°C | |
| AUG 16 | 25.5°C | 24.7°C | |
| AUG 17 | 25.5°C | 24.7°C | |
| AUG 18 | 25.5°C | 24.8°C | |
| AUG 19 | 25.5°C | 24.8°C | |
| AUG 20 | 25.5°C | 24.9°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 | 6°C |
| February | 0°C | 4°C | 7°C |
| March | 1°C | 6°C | 11°C |
| April | 7°C | 12°C | 17°C |
| May | 11°C | 17°C | 22°C |
| June | 15°C | 20°C | 25°C |
| July | 23°C | 25°C | 27°C |
| August | 22°C | 26°C | 29°C |
| September | 20°C | 23°C | 25°C |
| October | 13°C | 17°C | 20°C |
| November | 5°C | 11°C | 17°C |
| December | 1°C | 5°C | 8°C |
Keystone Lake: Water Temperature by Location
Keystone Lake: Weather Forecast
August 14
August 15
August 16
August 17
August 18
Location & Local Information
Keystone Lake in Pennsylvania follows the seasonal temperature patterns typical of small temperate reservoirs. In winter months the surface often hovers just above freezing, roughly 32–40°F (0–4°C) and can be ice-covered at times. Spring brings a steady rise, with surface temperatures commonly in the 40–60°F (4–15°C) range as the lake mixes and warms. Peak summer temperatures are usually reached between June and August, when surface waters commonly warm to about 68–78°F (20–26°C) and occasionally into the low 80s°F (27–28°C) on very hot, calm days. During autumn the lake cools back down, with surface readings typically falling to 50–65°F (10–18°C) before winter sets in. Deeper water remains cooler year-round and thermal stratification in summer can lead to colder conditions below the surface.
Swimming is generally possible during the warmer months when surface temperatures are comfortable, but it is allowed only where local rules, signage and safety conditions permit. Access may be limited to designated swim areas to keep bathers away from boat traffic and submerged hazards. Authorities may close swimming temporarily for public-health reasons such as harmful algal blooms, high bacterial counts, or poor weather, and ice on the lake in winter makes swimming unsafe. Always follow posted rules and recent water-quality advisories before entering the water.