Northwest Fishing Reports

I have been looking at the Fishing Forecast for a selected lake in the Historical Data tool and I am a bit confused. When I request a Forecast how is the forecast calculated? Why does the forecast seem to extend farther into future some lakes than for others?

It depends on things like the number of reports for the lake and also whether the lake is year-round or not. As we continue to add reports these forecast tools will get more accurate as well.