Jääsjärvi water temperature
Jääsjärvi, Hartola · Lake
The current water temperature at Jääsjärvi is 13.5 °C (as of September 19, 2026, source: official monitoring networks).
Lakes stratify in summer: bathing-warm on top, markedly colder a few metres down. Measurements are taken at the surface — right where you swim.
Measurement series & statistics
This measurement series includes 59 data points since July 23, 2026.
Lowest recorded value: 13.5 °C on September 19, 2026 · highest value: 19.7 °C on August 1, 2026.
In September, temperatures have ranged between 13.5 °C and 17.2 °C.
The current value is 1.5 °C below the September average of this series.
Nearby waters
Frequently asked questions
Can you swim at Jääsjärvi right now?
The current water temperature is 13.5 °C. See live swimming conditions, weather and quality in the BrrChecker app.
How warm is the water at Jääsjärvi?
Currently 13.5 °C (updated continuously).
How warm is at Jääsjärvi in September?
In September, the water temperature recently averaged 15.0 °C.
When is the water warmest at Jääsjärvi?
Across the measurement record, July is on average the warmest month (18.4 °C).
