Knight Reservoir — Current Water Temperature, Annual Trends and Forecast
This page provides information on the current water temperature in Knight Reservoir, trends, monthly ranges and the forecast for the coming days.
Current Water Temperature
Water Temperature in Knight Reservoir today is 17.5°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 |
|---|---|---|---|
| SEP 15 | 18.2°C | 21.0°C | |
| SEP 16 | 18.7°C | 21.0°C | |
| SEP 17 | 18.8°C | 21.0°C | |
| SEP 18 | 18.4°C | 21.0°C | |
| SEP 19 | 18.5°C | 21.0°C | |
| SEP 20 | 17.6°C | 21.0°C | |
| SEP 21 | 18.0°C | 21.0°C | |
| SEP 22 | 17.3°C | 21.0°C | |
| SEP 23 | 21.0°C | 17.7°C | |
| SEP 24 | 21.0°C | 17.9°C | |
| SEP 25 | 21.0°C | 18.0°C | |
| SEP 26 | 21.0°C | 18.2°C | |
| SEP 27 | 21.0°C | 18.4°C | |
| SEP 28 | 21.0°C | 18.6°C | |
| SEP 29 | 21.0°C | 18.7°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 | 21°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 |
Knight Reservoir: Water Temperature by Location
Knight Reservoir: Weather Forecast
September 23
September 24
September 25
September 26
September 27
Location & Local Information
#Surrey
Knight Reservoir in Surrey is one of the Thames-side storage reservoirs serving the region. Water temperatures vary with the seasons and depth: in winter surface temperatures commonly sit around 4–8 °C (39–46 °F), spring warms to roughly 8–14 °C (46–57 °F), and summer surface readings often reach 16–22 °C (61–72 °F), though brief heatwaves can push them slightly higher. Autumn sees a cooling back to about 10–15 °C (50–59 °F). Deeper layers remain noticeably colder than the surface, and local weather and river inflows influence how quickly the reservoir warms or cools.
Swimming at Knight Reservoir is generally not allowed. The site is managed mainly for water storage and supply, so access is restricted to protect water quality and reduce risks from cold water, currents and submerged structures; for these safety and operational reasons informal bathing is discouraged or prohibited. Visitors instead use the surrounding paths for walking, cycling and birdwatching. Nearby points of interest include riverside stretches of the Thames, the Runnymede memorial, family attractions such as Thorpe Park and the towns of Staines and Sunbury with their parks and riverside amenities.