When to Fish

is a practical adviser for every fisherman, who knows, that the catch isn’t just a question of luck. Based on location, weather, season and other data, predicted activity of the freshwater fish and hunting conditions are calculated.

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Fish activity forecast

Our forecast calculates the activity of various kinds of fish based on their preferences such as the temperature, pressure, precipitation, cloudiness…

Solunar calendar

The Solunar calendar is based on the solunar theory created by John Alden Knight in 1926. This theory stays that the mutual positioning and influencing of the moon and the sun has an impact on the behaviour of fish and other animals.


Barometer is showing pressure forecast and its changes and can help to predict impact on the fish activity.


Forecast for hunt conditions: carp, grass carp, zander, pike, catfish, bass, perch, bream, crappie, barbel, tench, trout, crucian carp, grayling, nase, eel, asp, roach, chub
Forecast for general fish activity
Forecast for weather, pressure, wind etc
Current moon phase
Solunar predictions

Forecast in application is not a garancy of catch
– only freshwater fishing
– the app provides prediction for all supported fish, regardless of their occurrence

Premium Membership


With the Premium Membership you will get half year’s subscription for:
Hourly forecasts for today and tomorrow
Daily forecasts for upcoming 5 days
Unlimited number of selected water areas (places)
Sharing of your saved places
Daily and hourly solunar predictions for the next three months
Possibility to project the solunar calculations to the classic calculations
Hourly barometer forecasts for two days
Forecasts contain fishing conditions and fish activity