How the Bite Score Works
Every lake on this site gets a daily bite score between 0 and 100. It's a single number that summarizes how favorable today's conditions are for catching fish. Here's exactly how it's calculated.
The scale
Our Scoring Approach
The score combines five environmental factors. The weighting reflects established fishing science and decades of pressure and solunar research — not a claim of precise percentages. Pressure and moon phase carry more influence because the literature most consistently links them to fish activity; the others provide supporting context.
Barometric Pressure
Highest influenceThe single strongest environmental trigger for fish feeding. Pressure is pulled from the current weather reading at each lake's coordinates. A falling barometer (pressure dropping 2+ mb since yesterday) scores highest — fish sense the change and feed aggressively ahead of it. Stable pressure scores moderately. Rising pressure after a front has passed scores lowest, as fish typically go deep and go quiet.
Solunar / Moon Phase
High influenceBased on moon illumination fraction calculated for the date. New moon and full moon periods score highest — gravitational pull on water is strongest, and solunar theory (first published by John Alden Knight in 1936 and widely used by serious anglers since) holds that fish feed most actively near these phases. Quarter moon periods score lowest.
Wind Speed
Moderate influenceModerate wind (5-15 mph) scores best. It breaks surface glare, pushes baitfish toward windward banks, and increases oxygen mixing — all of which trigger feeding. Dead calm conditions score moderately (fishable but slower). Winds above 20 mph make fishing difficult and score poorly.
Temperature Stability
Moderate influenceRapid temperature swings stress fish and suppress feeding. A stable air temperature (less than 2°F change over 24 hours) scores highest. Swings above 8°F — typical of a cold front passage — score lowest. This factor builds accuracy as the cron accumulates daily readings: the second day onward uses the actual prior reading; the first day defaults to stable.
Cloud Cover
Supporting factorOvercast skies (60%+ cloud cover) score highest. Low light conditions reduce fish wariness, particularly for predators like bass and walleye that rely on ambush. Bluebird high-pressure days with full sun score lowest — fish tend to push deep or into shade and feed shorter windows near dawn and dusk.
Data sources
- Weather data (pressure, wind, temperature, cloud cover) is pulled from OpenWeatherMap's Current Weather API at each lake's coordinates, once daily at 6am Central.
- Moon phase and illumination are calculated using SunCalc, an open-source astronomical library based on algorithms by Vladimir Agafonkin.
What the score doesn't account for
The bite score is an environmental conditions index, not a guarantee. It doesn't factor in:
- Water temperature vs. species preference (planned for a future update using USGS gauge data where available)
- Seasonal patterns and spawn timing specific to each lake
- Current fishing pressure and boat traffic
- Recent rainfall and water clarity
- Your skill level, presentation, and local knowledge — which still matter most
The score updates once daily. Use it as one input alongside the full fishing report for your lake, the live conditions tab, and your own knowledge of the water.