Water-quality measurements for lakes across 49 US states, as published by the EPA and state agencies. Ontario and Québec carry provincial measurements. Country hubs publish official ratings, attributed to the agency that issued them. Clarity, phosphorus, nitrogen, algae, and turbidity, plus depth and fish, shown as reported.

Email address

Lakes by Place

Lakes by State Lakes by Country Choose Your State Counties Watersheds Rivers by State

Browse Lakes

All Lakes Lake Map Global Lake Map Search Lakes Compare Lakes Recently Sampled

Rankings

Cleanest Lakes Clearest Water Largest Lakes Deepest Lakes Best Lakes by Activity Cleaner Lake Finder

Conditions

Water Temperature Algae Advisories Safe to Eat?Live Conditions Ice-Out Dates Invasive Species

Fishing

Fishing Guides Fishing Forecast Fish Species State Record Fish DNR Reports License Costs

Explore

Lake Travel & Lodging State Parks Boundary Waters Where to Wakesurf Waterfalls by State Hot Springs by State

Data & Trends

State of America’s Lakes Report Trend Reports Climate & Trends Oligotrophic Lakes Where the Data Comes From Data Sources

Learn

Articles Answers & Q&A Long-Form Guides Swimming Safety Glossary Tools

About Editorial Team Contact Methodology Editorial Policy Fact-Checking Corrections Disclaimer Privacy Policy Terms Support DMCA

Supported by advertising. LakeQuality is free to read; ads never influence our rankings or the measurements we show — see our editorial policy.

Lodging results and prices come from Stay22, which sources live availability from Booking.com, Vrbo, and Expedia. Booking through those links may earn us a commission at no extra cost to you, and never changes what a lake’s page shows or where it ranks.

US lake pages show samples from the EPA Water Quality Portal and state agencies beside the EPA National Lakes Assessment condition class for each lake’s ecoregion. Canadian measurements come from provincial open-data programmes, not the EPA. EU bathing waters use the EEA Bathing Water Directive. International named-lake chemistry is attributed on each country page. See data sources and methodology. Not affiliated with any government agency.

Powered by ColdPress

LakeQuality on Instagram LakeQuality on Facebook LakeQuality on YouTube