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 18.9°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 |
|---|---|---|---|
| JUN 23 | 18.0°C | 17.0°C | |
| JUN 24 | 18.0°C | 17.0°C | |
| JUN 25 | 17.6°C | 17.0°C | |
| JUN 26 | 17.7°C | 17.0°C | |
| JUN 27 | 17.8°C | 17.0°C | |
| JUN 28 | 17.8°C | 17.0°C | |
| JUN 29 | 18.5°C | 17.0°C | |
| JUN 30 | 18.8°C | 17.0°C | |
| JUL 1 | 20.0°C | 19.0°C | |
| JUL 2 | 20.0°C | 19.0°C | |
| JUL 3 | 20.0°C | 19.1°C | |
| JUL 4 | 20.0°C | 19.1°C | |
| JUL 5 | 20.0°C | 19.2°C | |
| JUL 6 | 20.0°C | 19.2°C | |
| JUL 7 | 20.0°C | 19.3°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 | 5°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
July 1
July 2
July 3
July 4
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.