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 14.2°C.
Water Temperature: Daily Trends, Historical Records, and Forecast
⚠️ As of today, the minimum water temperature ranges from 54°F (12°C) to 60°F (15°C). The water is significantly warmer, and swimming becomes possible for most people. However, caution may still be required for prolonged stays in the water, as extended exposure can cause discomfort. This is a suitable temperature range for short swims and for those accustomed to cooler water. For more comfortable swimming, it is recommended to use proper gear. 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 | 14.3°C | 20.0°C | |
| JUN 4 | 14.3°C | 20.0°C | |
| JUN 5 | 14.3°C | 20.0°C | |
| JUN 6 | 14.3°C | 20.0°C | |
| JUN 7 | 14.3°C | 20.0°C | |
| JUN 8 | 14.3°C | 20.0°C | |
| JUN 10 | 14.3°C | 20.0°C | |
| JUN 11 | 20.0°C | 14.5°C | |
| JUN 12 | 20.0°C | 14.8°C | |
| JUN 13 | 20.0°C | 15.1°C | |
| JUN 14 | 20.0°C | 15.4°C | |
| JUN 15 | 20.0°C | 15.7°C | |
| JUN 16 | 20.0°C | 15.9°C | |
| JUN 17 | 20.0°C | 16.2°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
June 9
June 10
June 11
June 12
June 13
June 14
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.