Finnsjön — Current Water Temperature, Annual Trends and Forecast
This page provides information on the current water temperature in Finnsjön, trends, monthly ranges and the forecast for the coming days.
Current Water Temperature
Water Temperature in Finnsjön today is 18.6°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 24 | 17.6°C | 20.0°C | |
| AUG 25 | 17.6°C | 20.0°C | |
| AUG 26 | 17.6°C | 20.0°C | |
| AUG 27 | 17.6°C | 20.0°C | |
| AUG 28 | 17.9°C | 20.0°C | |
| AUG 29 | 17.8°C | 20.0°C | |
| AUG 30 | 17.8°C | 20.0°C | |
| AUG 31 | 17.8°C | 20.0°C | |
| SEP 1 | 17.0°C | 18.5°C | |
| SEP 2 | 17.0°C | 18.4°C | |
| SEP 3 | 17.0°C | 18.4°C | |
| SEP 4 | 17.0°C | 18.3°C | |
| SEP 5 | 17.0°C | 18.2°C | |
| SEP 6 | 17.0°C | 18.1°C | |
| SEP 7 | 17.0°C | 18.0°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 | 3°C | 6°C |
| April | 1°C | 5°C | 8°C |
| May | 6°C | 11°C | 17°C |
| June | 12°C | 18°C | 23°C |
| July | 13°C | 19°C | 24°C |
| August | 14°C | 20°C | 25°C |
| September | 11°C | 17°C | 22°C |
| October | 5°C | 9°C | 12°C |
| November | 1°C | 5°C | 8°C |
| December | 0°C | 3°C | 6°C |
Finnsjön: Water Temperature by Location
Finnsjön: Weather Forecast
September 1
September 2
September 3
September 4
Location & Local Information
Finnsjön in Uppsala County typically follows the seasonal temperature patterns of small inland Swedish lakes. After winter ice, surface temperatures in early spring often range from about 0–6 °C (32–43 °F) as melting progresses. By late spring and early summer the water commonly warms to roughly 6–15 °C (43–59 °F), and peak summer temperatures can reach somewhere near 15–22 °C (59–72 °F) in warm years, especially in shallower bays. In autumn the lake cools again, generally falling to about 5–12 °C (41–54 °F) before refreezing. Local weather, depth, inflows and wind conditions influence these figures, so actual temperatures at a given time can differ.
Swimming at Finnsjön is generally possible and often practiced during the warmer months, given Sweden’s broad public access traditions and the lack of widespread prohibitions on bathing in natural lakes. Suitability for swimming depends on current water quality, weather and safety conditions; algae, sudden depth changes or cold temperatures can make bathing inadvisable outside midsummer. Ice swimming or winter bathing is undertaken by some, but requires proper precautions and knowledge of ice safety. Visitors should observe any local notices, use common-sense precautions, and test conditions before entering the water.