Observed arrival · 2026-11-09
Järvisää tracks Finland’s lakes, one freeze at a time
A Finnish lake guide reports water temperatures, ice conditions, blue-green algae risk, and forecasts for 15,019 lakes.
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- For
- Finnish residents and lake users checking nearby waters
- Worth noticing
- The homepage names its data sources and says most lake temperatures are modelled, then compared daily with measurements.
Field notes
The homepage breaks conditions into four regions and lists specific lakes expected to freeze next, including Oijärvi and Pöyrisjärvi. Its source note distinguishes measurement and observation inputs from modelled temperatures, which it says are checked against measurements daily. The ice guidance is explicit about a key limitation: estimates are not a substitute for measuring conditions on the lake.
Observed signals
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Editorial observations of this landing page, not a rating.
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