Isojärvi — Current Water Temperature, Annual Trends and Forecast
This page provides information on the current water temperature in Isojärvi, trends, monthly ranges and the forecast for the coming days.
Current Water Temperature
Water Temperature in Isojärvi today is 4°C.
Water Temperature: Daily Trends, Historical Records, and Forecast
❌ As of today, the minimum water temperature ranges less than 41°F (5°C). Such water is extremely cold and not recommended for swimming without proper preparation. In these conditions, the risk of hypothermia is very high, and prolonged exposure to the water can be hazardous to your health. If you decide to swim, it is important to have the appropriate gear, such as a wetsuit. Typically, only experienced swimmers or those who practice winter swimming venture into such waters. 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 |
|---|---|---|---|
| APR 11 | 1.7°C | 3.0°C | |
| APR 12 | 1.9°C | 3.0°C | |
| APR 13 | 2.2°C | 3.0°C | |
| APR 14 | 2.7°C | 3.0°C | |
| APR 15 | 2.9°C | 3.0°C | |
| APR 16 | 3.0°C | 3.0°C | |
| APR 17 | 3.2°C | 3.0°C | |
| APR 18 | 3.8°C | 3.0°C | |
| APR 19 | 3.0°C | 4.0°C | |
| APR 20 | 3.0°C | 3.9°C | |
| APR 21 | 3.0°C | 3.9°C | |
| APR 22 | 3.0°C | 3.8°C | |
| APR 23 | 3.0°C | 3.8°C | |
| APR 24 | 3.0°C | 3.7°C | |
| APR 25 | 3.0°C | 3.7°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 | 0°C | 2°C | 5°C |
| February | 0°C | 2°C | 5°C |
| March | 0°C | 2°C | 5°C |
| April | 0°C | 3°C | 6°C |
| May | 7°C | 12°C | 18°C |
| June | 11°C | 17°C | 22°C |
| July | 14°C | 20°C | 25°C |
| August | 14°C | 20°C | 25°C |
| September | 10°C | 15°C | 21°C |
| October | 4°C | 8°C | 11°C |
| November | 2°C | 6°C | 9°C |
| December | 0°C | 2°C | 5°C |
Isojärvi: Water Temperature by Location
Isojärvi: Weather Forecast
April 19
April 20
April 21
April 22
April 23
April 24
Location & Local Information
Isojärvi, meaning Large Lake, is a prominent, shallow-to-medium depth lake located in the Satakunta region, primarily within the municipalities of Pomarkku and Siikainen. Swimming is generally permitted along the lake's extensive shoreline and at designated public beaches, a fundamental right protected by Finland's Everyman’s Rights. This principle grants public freedom to use natural waters for recreation. Due to its size and relatively moderate depth, the lake's water quality is typically monitored during the summer season to ensure it remains suitable for safe seasonal bathing.
The water temperature in Isojärvi follows a distinct annual cycle. During the long winter, from approximately December to April, the lake is generally covered by ice, and the water temperature below the surface consistently hovers between 0∘C and 4∘C. Given its shallower average depth of around three meters, Isojärvi can warm up relatively quickly once the ice melts. The most pleasant swimming season is concentrated in July. During this peak summer month, surface temperatures in sun-exposed areas typically reach an approximate range of 20∘C to 23∘C. Outside of the brief summer period, the water remains too cold for casual swimmers.