Queen Mary Reservoir — Current Water Temperature, Annual Trends and Forecast
This page provides information on the current water temperature in Queen Mary Reservoir, trends, monthly ranges and the forecast for the coming days.
Current Water Temperature
Water Temperature in Queen Mary Reservoir today is 18.1°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 |
|---|---|---|---|
| SEP 15 | 18.2°C | 21.0°C | |
| SEP 16 | 19.0°C | 21.0°C | |
| SEP 17 | 19.2°C | 21.0°C | |
| SEP 18 | 19.1°C | 21.0°C | |
| SEP 19 | 18.4°C | 21.0°C | |
| SEP 20 | 18.2°C | 21.0°C | |
| SEP 21 | 18.9°C | 21.0°C | |
| SEP 22 | 18.5°C | 21.0°C | |
| SEP 23 | 21.0°C | 18.2°C | |
| SEP 24 | 21.0°C | 18.4°C | |
| SEP 25 | 21.0°C | 18.5°C | |
| SEP 26 | 21.0°C | 18.7°C | |
| SEP 27 | 21.0°C | 18.8°C | |
| SEP 28 | 21.0°C | 19.0°C | |
| SEP 29 | 21.0°C | 19.1°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 |
Queen Mary Reservoir: Water Temperature by Location
Queen Mary Reservoir: Weather Forecast
September 23
September 24
September 25
September 26
September 27
Location & Local Information
#Surrey
Queen Mary Reservoir’s surface temperatures vary with the seasons and local weather. In winter the water typically sits around 4–8 °C (39–46 °F), rising through spring to roughly 6–14 °C (43–57 °F). By summer the top layers commonly warm to about 15–22 °C (59–72 °F), while autumn sees cooling back to the 8–14 °C (46–57 °F) range. Deeper water remains colder year-round and sudden changes in air temperature or rainfall can shift surface readings quickly, so these figures are general rather than exact.
Open-water swimming is not permitted at Queen Mary Reservoir: it is a working drinking-water reservoir and access is restricted for safety, water-quality protection and operational reasons. Recreational activity is focused on managed uses such as sailing and shore-based birdwatching, and the perimeter paths are popular with walkers and cyclists. The site lies close to Walton-on-Thames and is within easy reach of attractions including Hampton Court Palace and the historic Runnymede meadows, making it a useful base for riverside walks and regional sightseeing even if swimming isn’t allowed.