Aldenham Reservoir — Current Water Temperature, Annual Trends and Forecast
This page provides information on the current water temperature in Aldenham Reservoir, trends, monthly ranges and the forecast for the coming days.
Current Water Temperature
Water Temperature in Aldenham Reservoir today is 19.6°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 |
|---|---|---|---|
| AUG 26 | 19.9°C | 23.0°C | |
| AUG 27 | 19.9°C | 23.0°C | |
| AUG 28 | 19.9°C | 23.0°C | |
| AUG 29 | 19.9°C | 23.0°C | |
| AUG 30 | 19.4°C | 23.0°C | |
| AUG 31 | 19.4°C | 23.0°C | |
| SEP 1 | 19.1°C | 21.0°C | |
| SEP 2 | 19.6°C | 21.0°C | |
| SEP 3 | 21.0°C | 19.7°C | |
| SEP 4 | 21.0°C | 19.7°C | |
| SEP 5 | 21.0°C | 19.8°C | |
| SEP 6 | 21.0°C | 19.9°C | |
| SEP 7 | 21.0°C | 20.0°C | |
| SEP 8 | 21.0°C | 20.0°C | |
| SEP 9 | 21.0°C | 20.1°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 | 8°C | 13°C | 17°C |
| May | 10°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 | 4°C | 9°C | 13°C |
| December | 4°C | 8°C | 11°C |
Aldenham Reservoir: Water Temperature by Location
Aldenham Reservoir: Weather Forecast
September 3
September 4
September 5
September 6
September 7
Location & Local Information
#Hertfordshire
Aldenham Reservoir is a shallow, sheltered body of water whose temperature varies with the seasons. In summer the surface typically warms to around 16–21 °C (61–70 °F), offering relatively mild conditions for brief wading or cold-water swims for experienced people. Spring and autumn temperatures commonly sit between 8–15 °C (46–59 °F), while winter water can fall to about 4–7 °C (39–45 °F), occasionally dipping nearer to 1–3 °C (34–37 °F) during very cold spells. Because the reservoir is used for sailing and other water sports and because of safety and water-quality considerations, casual open swimming is generally not allowed; organised, supervised events or club-approved sessions may be permitted under controlled conditions.
Beyond the water itself, the site is integrated with Aldenham Country Park and its family amenities, offering footpaths, picnic areas and wildlife viewing. The reservoir hosts a sailing club and windsurfing activities, and nearby towns such as Elstree and Borehamwood provide shops and the film studios, while the surrounding Hertfordshire countryside offers easy walking and local heritage to explore.