Solunar Bite Predictor
Calculate major and minor daily fish feeding windows based on sun and moon transit coordinates.
Estimates only. Not a substitute for official wildlife regulations.
The logic of solunar theory: overhead & underfoot transits
Solunar theory was published in 1926 by John Alden Knight, who cataloged factors influencing wildlife behavior. The calculations are based on astronomical alignments of the sun and moon:
- Major Periods (2 Hours): Occur when the moon is directly overhead (lunar transit) or directly underfoot (antitransit/opposition). These represent peaks in gravitational pull, which can increase movement in both fish and game.
- Minor Periods (1 Hour): Coincide with moonrise and moonset. These are secondary activity periods that can stimulate feeding, especially if they occur during low-light hours.
- Moon Phase Influence: The full moon and new moon align with spring tides, creating higher tidal flow and trigger feeding triggers. Full moons also illuminate the night, shifting target feeding activity to dawn, dusk, or night hours.
Evenhanded Framing Note: Solunar prediction is a traditional heuristic, not a scientifically guaranteed formula. Wind speeds, rain fronts, localized water temp changes, and bait presence can easily override lunar predictions. Use this as a general planning guide rather than a rule.
Frequently Asked Questions
Solunar theory states that fish and animal activity is influenced by the relative positions of the sun and the moon. The theory predicts that fish feed more actively during specific times of day—major and minor periods—corresponding to moon transit (overhead), antitransit (underfoot), moonrise, and moonset.
Major periods last approximately 2 hours and occur when the moon is directly overhead (transit) or directly underfoot (antitransit). Minor periods last about 1 hour and coincide with moonrise and moonset. Major periods generally produce stronger fish activity than minor periods.
Yes. The full moon and new moon phases produce the strongest gravitational pulls, resulting in spring tides (higher tide variance) and higher biological activity. Full moon phases also provide high ambient light at night, which can trigger active low-light or nocturnal feeding.
Solunar periods are a traditional heuristic. While scientific studies confirm that tidal currents (driven by the moon) and light levels (driven by moon phase) directly influence marine feeding behavior, solunar periods are not a guarantee of catching fish, as local factors like wind, barometric pressure, and water temperature take precedence.