Sliven — Current Water Temperature, Annual Trends and Forecast
This page provides information on the current water temperature in Sliven, trends, monthly ranges and the forecast for the coming days.
Current Water Temperature
Water Temperature in Sliven today is 21.7°C.
Water Temperature: Daily Trends, Historical Records, and Forecast
✅ As of today, the minimum water temperature ranges from 68°F (20°C) to 74°F (23°C). The water is warm and pleasant for swimming, and in this range, one can stay in the water for extended periods without the risk of hypothermia. This is the ideal temperature for relaxation, swimming, and water sports. Families with children, as well as outdoor enthusiasts, will enjoy swimming and time spent in the water. For most people, this is the optimal temperature for a comfortable beach experience. 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 | 20.8°C | 20.0°C | |
| JUN 4 | 20.8°C | 20.0°C | |
| JUN 5 | 20.9°C | 20.0°C | |
| JUN 6 | 21.4°C | 20.0°C | |
| JUN 7 | 21.1°C | 20.0°C | |
| JUN 8 | 21.0°C | 20.0°C | |
| JUN 10 | 21.7°C | 20.0°C | |
| JUN 11 | 20.0°C | 21.6°C | |
| JUN 12 | 20.0°C | 21.5°C | |
| JUN 13 | 20.0°C | 21.4°C | |
| JUN 14 | 20.0°C | 21.4°C | |
| JUN 15 | 20.0°C | 21.3°C | |
| JUN 16 | 20.0°C | 21.2°C | |
| JUN 17 | 20.0°C | 21.1°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 | 8°C | 13°C |
| February | 3°C | 9°C | 13°C |
| March | 5°C | 10°C | 15°C |
| April | 9°C | 13°C | 17°C |
| May | 10°C | 16°C | 22°C |
| June | 15°C | 20°C | 25°C |
| July | 18°C | 23°C | 28°C |
| August | 18°C | 23°C | 28°C |
| September | 15°C | 20°C | 25°C |
| October | 13°C | 17°C | 20°C |
| November | 9°C | 13°C | 16°C |
| December | 4°C | 9°C | 13°C |
Sliven: Weather Forecast
June 9
June 10
June 11
June 12
June 13
June 14
Location & Local Information
Sliven (Сливен) lies along the Tundzha River and is surrounded by small reservoirs and mountain streams descending from the eastern Balkan foothills. Seasonal water temperatures in these inland bodies vary considerably: during spring the river and lowland reservoirs commonly range from about 6–15 °C (43–59 °F), warming in summer to roughly 18–26 °C (64–79 °F) in typical years and sometimes reaching 27–28 °C (81–82 °F) in heat waves. Autumn sees cooling to roughly 8–18 °C (46–64 °F), while winter temperatures in exposed rivers and reservoirs can fall to near freezing, about 0–5 °C (32–41 °F). Mountain streams and shaded river sections remain noticeably colder year-round, often only 8–16 °C (46–61 °F) even in summer because of spring-fed flow and snowmelt.
Swimming in Sliven’s rivers and reservoirs is physically possible during the warmer months but is subject to local rules and safety considerations. Many sites are used for irrigation, fisheries or as drinking-water catchments and may have access restrictions or variable water quality; lifeguards are generally absent and currents, submerged obstacles and sudden depth changes are common. For comfortable bathing, locals swim mainly in midsummer when surface temperatures exceed about 20 °C (68 °F). Visitors should check local signage or municipal guidance, avoid restricted reservoirs and take usual precautions for natural-water swimming.