Guide · 6 min read
How the USTideCharts Fishing Score Works
Exactly what goes into the 0–100 fishing score on every location page — the six factors, how they're weighted, and what the score can and can't tell you.
Every location page on USTideCharts shows a fishing score from 0 to 100, updated continuously through the day. It isn't a guess and it isn't magic — it's a weighted blend of six measurable conditions, computed the same way for every hour at every station. This page explains the formula, because a score you can't interrogate is a score you shouldn't trust.
The single heaviest factor is tide movement, at roughly a third of the score. We compute the rate of change of the tide — how many feet per hour the water is rising or falling right now — from NOAA's own harmonic predictions. Fast-moving water moves bait and turns predators on; slack water turns them off. A ripping mid-tide scores high whether the water is coming in or going out, because both directions concentrate feeding, just at different kinds of spots.
The other five factors
Light is next, at about a quarter of the score. Dawn and dusk are the most reliable bite windows in inshore fishing, so hours near sunrise and sunset get a strong boost, computed from the actual sun times at that station's coordinates — not a generic clock.
Moon phase contributes the solunar component: days near new and full moons score higher because the same alignment that creates spring tides is associated with stronger feeding activity. Wind matters at about fifteen percent — a light breeze is neutral-to-good, but as wind climbs past fresh into strong, casting, boat control, and water clarity all degrade, and the score reflects it. The last slices go to general weather (a front or thunderstorm knocks points off) and water temperature, which is scored against the preferred range of the species typical for that region.
The 'Best windows today' list is the same math run for every hour of the day, then grouped into the stretches that score highest. A day's headline number is its best window, not its average — a day with one excellent dawn window and a dead afternoon is still a day worth fishing, and the score says so.
What the score is not
The score doesn't know what you fish for, and it can't see bait in the water, boat traffic, or the school of fish that showed up for no reason at all. Treat it the way you'd treat a strong weather forecast: an honest summary of the conditions that are knowable in advance. It stacks the odds; it doesn't guarantee the outcome. If the score says 85 and your local knowledge says the spot needs a west swell to fish well, believe your local knowledge.
Everything feeding the score is public, primary-source data: tide predictions from NOAA CO-OPS harmonic stations, weather and marine conditions from the Open-Meteo forecast models, and astronomical calculations for sun and moon. When a live feed is unreachable we say so on the page with a visible 'sample data' badge rather than quietly showing stale numbers.
