Porth Reservoir — Current Water Temperature, Annual Trends and Forecast
This page provides information on the current water temperature in Porth Reservoir, trends, monthly ranges and the forecast for the coming days.
Current Water Temperature
Water Temperature in Porth Reservoir today is 17.2°C.
Water Temperature: Daily Trends, Historical Records, and Forecast
⚠️ As of today, the minimum water temperature ranges from 60°F (15°C) to 65°F (18°C). The water is comfortable for most people, making it an ideal range for water sports enthusiasts. The temperature does not cause significant discomfort, and swimming will be pleasant for the majority. However, it's important to remember that prolonged exposure to the water can still lead to cooling, so it's essential to monitor the time spent in the water, especially for children or elderly people. 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 25 | 16.0°C | 20.0°C | |
| JUN 26 | 16.0°C | 20.0°C | |
| JUN 27 | 16.3°C | 20.0°C | |
| JUN 28 | 15.8°C | 20.0°C | |
| JUN 29 | 15.8°C | 20.0°C | |
| JUN 30 | 16.9°C | 20.0°C | |
| JUL 1 | 17.2°C | 21.0°C | |
| JUL 2 | 17.2°C | 21.0°C | |
| JUL 3 | 21.0°C | 17.4°C | |
| JUL 4 | 21.0°C | 17.6°C | |
| JUL 5 | 21.0°C | 17.8°C | |
| JUL 6 | 21.0°C | 18.0°C | |
| JUL 7 | 21.0°C | 18.2°C | |
| JUL 8 | 21.0°C | 18.3°C | |
| JUL 9 | 21.0°C | 18.5°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 | 4°C | 8°C | 11°C |
| February | 4°C | 8°C | 11°C |
| March | 5°C | 9°C | 12°C |
| April | 7°C | 11°C | 14°C |
| May | 7°C | 12°C | 18°C |
| June | 14°C | 20°C | 25°C |
| July | 16°C | 21°C | 26°C |
| August | 17°C | 22°C | 27°C |
| September | 12°C | 18°C | 23°C |
| October | 7°C | 11°C | 14°C |
| November | 5°C | 9°C | 12°C |
| December | 4°C | 8°C | 11°C |
Porth Reservoir: Water Temperature by Location
Porth Reservoir: Weather Forecast
July 3
July 4
July 5
July 6
July 7
Location & Local Information
#Cornwall
Porth Reservoir in Cornwall sits quietly among wooded banks and farmland, and its water temperature reflects the mild maritime climate. Seasonal surface temperatures typically range from about 6–9 °C (43–48 °F) in winter, rising to roughly 8–14 °C (46–57 °F) in spring. In summer the reservoir can warm to around 15–20 °C (59–68 °F) at the surface on sunnier days, while early autumn sees a gradual fall back into the 10–14 °C (50–57 °F) band. Deeper water remains noticeably colder year-round, so recorded temperatures can vary with depth and weather.
Swimming at Porth Reservoir is largely an unsupervised, wild swimming activity and may be discouraged or restricted depending on the landowner or water utility, mainly for safety and water-quality reasons. There are risks from cold shock, hidden underwater hazards and lack of lifeguards, so visitors should check local signage and heed any official guidance before entering. The area nonetheless appeals to outdoor enthusiasts; nearby attractions include coastal paths and beaches, local villages with cafés and shops, and popular surf spots and cliff walks along the Cornish coast.