The UK Fishing Forecast App — Know Exactly When to Fish
Solunar tables, barometric pressure, moon phases, and 5-day forecasts — calculate the best fishing times for any UK location, free.
How Fish On! Calculates the Best Fishing Times
Finding the best fishing times isn't guesswork — it's science. Fish On!'s forecast engine combines four key variables to calculate peak feeding windows for any UK location: solunar periods (the influence of sun and moon positions on fish activity), barometric pressure and trend (fish are most active when pressure is stable or falling gradually), water temperature (which determines fish metabolism and feeding intensity), and tidal state for coastal locations. These variables are weighted by species — the best fishing times for carp differ from bass or trout — and calculated for your exact GPS coordinates in real time. The result is a compound bite prediction that tells you not just whether today is worth fishing, but precisely which hours offer the highest probability of fish feeding.
Solunar Theory: The Science Behind Best Fishing Times
Solunar theory was first documented by John Alden Knight in 1936 after he noticed fish activity spiking at predictable intervals tied to the positions of the sun and moon. Decades of angler observations since have consistently supported the core principle: fish feed most aggressively during major solunar periods (when moon is overhead or underfoot, lasting 1-2 hours, twice daily) and moderately during minor periods (moonrise and moonset). Fish On! calculates these periods to the minute for your location and displays them as a bite probability chart across each day — so you can see exactly when the feeding windows open and close. Plan your session around a major period and you'll consistently be on the bank when fish are active.
Barometric Pressure and the Best Fishing Times
Of all environmental variables, barometric pressure is the one experienced anglers monitor most closely — and for good reason. Fish have swim bladders that are sensitive to pressure changes, and shifts in atmospheric pressure directly affect their comfort and willingness to feed. A steady or slowly falling pressure is generally the best fishing condition — fish are comfortable and actively hunting. A rapidly rising pressure after a weather front often switches feeding off for 12-24 hours. Fish On! displays current pressure and the trend (rising, falling, or stable) for your location, and factors this into the composite forecast score. Over time, logging your catches against pressure readings reveals your personal pressure-to-catch correlation for your specific venues.
5-Day Fishing Forecast: Plan the Week Ahead
The best fishing sessions start with the right day. Fish On!'s 5-day fishing forecast gives you a composite rating for each day ahead — combining solunar quality, predicted pressure trends, temperature forecasts, and wind conditions into a single score from 1 to 10. Compare the next five days at a glance and identify the strongest fishing window for your target species. For working anglers who can only get out once or twice a week, this planning capability alone is worth the download. Stop booking sessions on poor-forecast days and saving your time for the days when everything aligns.
Species-Specific Fishing Time Predictions
The best fishing times vary by species. Carp feed most aggressively in warm water (15-25°C) under falling pressure, with dawn and dusk as their natural feeding peaks amplified by solunar periods. Bass respond to tidal movement first — the last two hours of flood on a rock mark — with solunar and pressure as secondary factors. Tench are classic early morning feeders, peaking at dawn on warm summer days with stable or rising pressure. Barbel come on strongest in flood conditions and overnight in warmer months. Pike and perch are winter-active and feed well in cold, clear conditions that deter other species. Fish On!'s species selector adjusts the forecast weighting for your target species so the best fishing times shown are genuinely calibrated for what you're after.