About LakeCharts USA

LakeCharts USA turns public U.S. Geological Survey gauge data into one fast page per lake and river.

Data sources

• Water level, streamflow, water temperature: USGS Water Services instantaneous values (every 15–60 minutes) and daily values.
• Normal ranges and records for the date: USGS daily statistics — percentiles of approved daily means for each calendar date over the gauge’s record.
• Flood stages and record crests: NOAA National Water Prediction Service.
• Weather (air temperature, wind, gusts, pressure trend, 3-day forecast): NOAA National Weather Service gridpoint forecast for each page’s coordinates (api.weather.gov), refreshed daily; the “Air temp & weather now” tile refreshes live from the NWS hourly forecast. Air temperature is always labeled “Air temp”; water temperature is labeled “Water temp”.
• Water temperature: measured only — the page’s own USGS gauge or dam operator, or (labeled with its location and distance) a USGS temperature gauge on the same lake or the same river within 12 miles, or an in-lake Army Corps sensor. We never model or estimate it.
• Fishing report & conditions: a one-line summary built from the numbers on the page; “Best fishing times” uses solunar periods (moon overhead / underfoot / rise / set, computed with PyEphem), sunrise and sunset, the moon phase and local conditions (NWS pressure trend and wind, the 24-hour level or flow trend and water temperature). Main species come from the state agency where it publishes them per lake — Texas Parks and Wildlife lake pages, Georgia DNR fishing forecasts, TWRA where-to-fish pages (TN), Missouri Department of Conservation “Best Bets”, Oklahoma Wildlife “Fish Species of Interest”, Kentucky Fish & Wildlife’s fishing forecast, Virginia DWR waterbody pages, Minnesota DNR LakeFinder survey catches, Wisconsin DNR lake pages, NDOW (NV), Florida FWC sites & forecasts, and specific NYSDEC, SCDNR and Outdoor Alabama lake pages — each matched to one lake by name within the state and cited on the page; we never guess species; every page links its state agency’s official fishing report or forecast page where one exists.
• Reservoirs USGS doesn’t gauge: U.S. Army Corps of Engineers (Access2Water / CWMS Data API), Tennessee Valley Authority lake levels, Bureau of Reclamation Lower Colorado daily report, Texas Water Development Board (Water Data for Texas), Appalachian Power (AEP) hydro levels, Ameren Missouri (Lake of the Ozarks report), Brookfield Renewable (Safe Waters), Duke Energy’s public lake-level feed (Lake Norman, Lake James, Lake Wylie, Keowee, Jocassee and other Duke lakes; Duke’s local “100 ft = normal full pond” readings converted to feet above sea level with Duke’s published full-pond elevation), Reclamation’s Upper Colorado HydroData (Blue Mesa, Granby, Strawberry, McPhee and other Colorado, Utah, Wyoming and New Mexico reservoirs) and NOAA CO-OPS Great Lakes water levels (IGLD 1985) and water temperatures. Operator data is preliminary.
• Full pool, seasonal targets, percent full, releases and schedules: as published by the dam operator (Corps “top of conservation” pool levels, TVA operating guide, utility full-pond levels); source linked on each page.

Map

The map uses Leaflet and map tiles © OpenStreetMap contributors; marker colors are the same status as each page (vs normal for the date, or vs full pool where there is no long history).

Status colors

Much below normal (<10th percentile), below normal (10–24th), normal (25–75th), above normal (76–90th), much above normal (>90th) — the same classes USGS WaterWatch uses.

How the fishing rating works

1 to 10 = 1 base + up to 3 when a solunar period overlaps sunrise or sunset + up to 2 near a new or full moon + 0 to 4 for local conditions: pressure falling through the day +2 (steady or slowly rising +1, rising fast 0); daytime wind 4–15 mph +1 (over 20 mph or gusts over 30 mph −1); a steady lake level (±0.25 ft in 24 h) or steady river flow (±15%) +1 (river flow up more than 25% −1); water 55–75°F +1 (below 45°F or above 85°F −1). Days 2–7 use only sun, moon and the forecast pressure and wind.

Affiliate links

Some pages may include links to trip-planning partners. We may earn a commission at no cost to you.

Not for safety decisions

Recent readings are provisional. Always follow official flood warnings and posted lake notices.