Island Barn Reservoir — Current Water Temperature, Annual Trends and Forecast
This page provides information on the current water temperature in Island Barn Reservoir, trends, monthly ranges and the forecast for the coming days.
Current Water Temperature
Water Temperature in Island Barn Reservoir today is 14.9°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 | 17.0°C | 21.5°C | |
| JUN 4 | 16.3°C | 21.5°C | |
| JUN 5 | 16.3°C | 21.5°C | |
| JUN 6 | 16.3°C | 21.5°C | |
| JUN 7 | 16.2°C | 21.5°C | |
| JUN 8 | 15.1°C | 21.5°C | |
| JUN 10 | 15.1°C | 21.5°C | |
| JUN 11 | 21.5°C | 15.2°C | |
| JUN 12 | 21.5°C | 15.6°C | |
| JUN 13 | 21.5°C | 15.9°C | |
| JUN 14 | 21.5°C | 16.2°C | |
| JUN 15 | 21.5°C | 16.6°C | |
| JUN 16 | 21.5°C | 16.9°C | |
| JUN 17 | 21.5°C | 17.2°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 | 3°C | 7°C | 10°C |
| February | 4°C | 8°C | 11°C |
| March | 6°C | 10°C | 13°C |
| April | 9°C | 13°C | 17°C |
| May | 11°C | 17°C | 22°C |
| June | 14°C | 22°C | 28°C |
| July | 19°C | 24°C | 29°C |
| August | 18°C | 23°C | 28°C |
| September | 16°C | 21°C | 26°C |
| October | 11°C | 15°C | 19°C |
| November | 5°C | 9°C | 13°C |
| December | 4°C | 8°C | 11°C |
Island Barn Reservoir: Water Temperature by Location
Island Barn Reservoir: Weather Forecast
June 9
June 10
June 11
June 12
June 13
Location & Local Information
#Surrey
Island Barn Reservoir, on the outskirts of Walton-on-Thames in Surrey, typically shows seasonal water temperatures that reflect southern England's climate. In winter surface temperatures often fall to around 4–6 °C (39–43 °F). Spring sees a gradual rise to roughly 6–12 °C (43–54 °F) as daylight increases, while summer surface temperatures commonly reach 15–22 °C (59–72 °F) on warm spells. Autumn brings cooling waters in the region of 8–14 °C (46–57 °F). Local conditions such as wind, depth and inflow can produce variations, and deeper sections generally remain cooler than the surface.
Swimming in Island Barn Reservoir is not generally permitted. The site is a managed water body and wildlife area, and restrictions are in place to protect drinking-water quality, public safety and sensitive bird habitats; steep banks and submerged structures also create hazards. Visitors therefore tend to use nearby alternatives: the River Thames towpath and riverside walks, Walton town centre with cafés and shops, and adjacent green spaces popular with walkers and birdwatchers. These offer easier and safer options for recreation close to the reservoir.