Data sources
Where the numbers come from
Every data point on this site comes from a free, public, authoritative source. Nothing is scraped from paywalled sources or inferred from proprietary data.
Active sources
- NOAA CO-OPS (Tides & Currents)
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Tide predictions (high/low times and heights) and water temperature observations at tidal stations throughout the region. Used for every tidal fishing location — Sandy Point, Point Lookout, Kent Narrows, Cape Henlopen, Kiptopeke, etc.
- National Weather Service (NWS)
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Forecast conditions (air temperature, wind speed + direction, short forecast, rain probability) and active weather alerts. Used on every page. The NWS gridpoint pressure forecast also supplies the barometer trend at inland locations with no buoy.
- NDBC (National Data Buoy Center)
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Real-time conditions from the nearest offshore or bay buoy — wave height, water temperature, wind, and observed barometric pressure with its 3-hour tendency. Drives the wave-height factor and the observed-pressure barometer signal at coastal and bay locations.
- USGS Water Services
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Water temperature and streamflow (discharge + gage height, with a 24-hour trend) at inland gauges nationwide — from the Gunpowder and Savage tailwaters to the Madison, Missouri, Yellowstone, and Bighorn out West. Used when a location is not near a NOAA CO-OPS station; streamflow drives the river-flow factor for flow-sensitive species.
- State fishing reports
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Each location page surfaces its state’s current fishing report, and where a report is machine-parseable it also feeds a small recency factor in the score. Maryland’s DNR weekly report is parsed region-by-region; Delaware, Indiana, New York, Oklahoma, Oregon, and South Carolina are parsed at state level. States whose reports are PDF-only, app-rendered, or bot-blocked are linked rather than parsed. Each page also links its state’s fish-consumption advisory (mercury/PCB/PFAS guidance).
- Maryland Department of the Environment (MDE)
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Swim and water-quality advisories across Maryland beaches and tidal waters, fetched from the MDE Healthy Beaches ArcGIS feature service. Surfaced as the “water-quality advisory” factor in the fishing-day score.
- State fishery agencies for regulations
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Each state’s fishery agency is the authoritative source for size limits, creel limits, season windows, and gear restrictions — MD DNR, Delaware DNREC, VMRC and VA DWR, and the PRFC in our flagship region, through to Montana FWP, Colorado Parks & Wildlife, and every other state we cover. Each species record carries the exact URL we fetched and the date we last verified it. A verification script (
npm run verify:regs) snapshots each source URL and flags page-content drift on subsequent runs; it is run manually before each release.
Astronomical calculations
Sunrise, sunset, moon phase, moon illumination, and solunar major/minor periods are computed locally using published astronomical formulas (NOAA Solar Calculator for sun times; low-precision moon-position math for solunar). No API calls are needed for these — the math runs at build time.
What we don’t do
- We don’t aggregate user-submitted catch reports.
- We don’t infer conditions at locations without a real nearby station. If a reservoir doesn’t have a USGS temp gauge within range, the page shows “unavailable” — not a fabricated number.
- We don’t buy or license proprietary fishing-data feeds.
- We don’t rerank editorial content based on advertising relationships (see methodology).
Sibling site
itsabeachday.com data sources — the beach site’s equivalent page, shares most of the same underlying APIs plus sea-nettle and NDBC buoy data for ocean-specific conditions.