Lakes, ponds & beaches · refreshed daily
SwimZone reads bacteria and blue-green algae monitoring, plus recent rain, into one plain swim-safety read for the lake, pond, or beach you're headed to. Calm and sourced, for people who'd rather just know before they get in.
6,187 monitored waters · free · no account needed
Current reads across monitored waters, from New England lakes to the Gulf and the upper Midwest.
A single clear-to-swim, caution, or advisory verdict per water. Know at a glance, not after decoding a dashboard.
Fecal bacteria (E. coli) and cyanobacteria (blue-green algae), the two things that actually close a beach, shown side by side.
Built from official monitoring and advisories, refreshed as new samples and satellite bloom reports come in.
Every read cites its state or federal source, and is clear that conditions change fast between samples.
Water quality is local. A lake and the pond down the road aren't the same on the same day. Browse every monitored water, grouped by state.
Browse all 6,187 monitored waters →iPhone app · launching soon
The app puts your favorite waters' daily swim-safety read on your home screen and pings you the day a bacteria or algae advisory goes up, so you, your kids, and your dog stay out of bad water. The website stays free.