Triadelphia Reservoir — Current Water Temperature, Annual Trends and Forecast
This page provides information on the current water temperature in Triadelphia Reservoir, trends, monthly ranges and the forecast for the coming days.
Current Water Temperature
Water Temperature in Triadelphia Reservoir today is 18.8°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 |
|---|---|---|---|
| OCT 6 | 20.5°C | 16.5°C | |
| OCT 7 | 20.8°C | 16.5°C | |
| OCT 8 | 19.9°C | 16.5°C | |
| OCT 9 | 19.3°C | 16.5°C | |
| OCT 10 | 19.1°C | 16.5°C | |
| OCT 11 | 19.1°C | 16.5°C | |
| OCT 12 | 19.1°C | 16.5°C | |
| OCT 13 | 18.9°C | 16.5°C | |
| OCT 14 | 16.5°C | 18.7°C | |
| OCT 15 | 16.5°C | 18.6°C | |
| OCT 16 | 16.5°C | 18.5°C | |
| OCT 17 | 16.5°C | 18.3°C | |
| OCT 18 | 16.5°C | 18.2°C | |
| OCT 19 | 16.5°C | 18.1°C | |
| OCT 20 | 16.5°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 | 2°C | 5°C | 8°C |
| February | 1°C | 4°C | 7°C |
| March | 2°C | 7°C | 12°C |
| April | 9°C | 13°C | 18°C |
| May | 12°C | 18°C | 25°C |
| June | 18°C | 23°C | 27°C |
| July | 25°C | 28°C | 30°C |
| August | 21°C | 24°C | 28°C |
| September | 18°C | 22°C | 26°C |
| October | 11°C | 17°C | 22°C |
| November | 7°C | 13°C | 18°C |
| December | 3°C | 6°C | 9°C |
Triadelphia Reservoir: Water Temperature by Location
Triadelphia Reservoir: Weather Forecast
October 14
October 15
October 16
October 17
October 18
Location & Local Information
Triadelphia Reservoir in Maryland exhibits the typical seasonal temperature pattern of a mid‑Atlantic impoundment. Surface water in summer often warms into the low to mid‑70s °F (about 22–25 °C) and on hot spells can reach the upper 70s to around 80 °F (26–27 °C). Spring and early summer surface temperatures commonly range from the mid‑40s to mid‑60s °F (7–18 °C) as the water column mixes, while autumn cools back into the 50s–60s °F (10–18 °C). In winter the surface may be near freezing up to the low 40s °F (0–5 °C). Like other reservoirs, Triadelphia stratifies in summer so deeper water stays much colder—often in the 40s °F (4–9 °C)—which is important for anglers and boaters to note.
Swimming is generally not permitted at Triadelphia because the reservoir is managed primarily as part of the regional water‑supply system and restrictions are in place to protect drinking‑water quality and public safety. Prohibitions reduce contamination risk and address hazards such as cold‑water shock, underwater obstacles, variable depths and boat traffic. Visitors should follow posted rules and local agency guidance; recreational activities that are allowed in designated areas follow specific safety and water‑quality regulations.