Beach water quality, forecast daily
Beach bacteria tests take a day or more, and many beaches are only sampled once a week. We forecast water quality at individual California beaches every morning, and deliver it to the apps and outlets people already check before they go in.
Talk to usRight after it rains is when people most want to know whether it's safe to go in, and it's also when official data is at its oldest.
A water sample takes a day or more to process in the lab, so today's posting reflects yesterday's water or older.
Many beaches are tested weekly or monthly, especially outside summer. Between tests, there's little to go on.
Advisories live on county websites that most surfers, swimmers and parents never check.
A daily flag and a five-day outlook for each beach, set every morning before any new lab result comes in.
Years of county lab results across California, joined with rain, creek flow, tides, waves and sewer discharge records.
What drives bad water at a creek mouth is different from an open surf break, so each beach gets its own model.
We show the county's official call next to our forecast, never in place of it. When data is too stale to call, we say so.
We work with the people who already reach beachgoers, and with the agencies whose data makes this possible.
Interested in a pilot, a data partnership or the research? We'd love to hear from you.
riley@coastalsignalinc.com