Beach · Collier County · FL
Is 4TH AVENUE SOUTH BEACH safe to swim?
Recent heavy rain may have spiked bacteria since the last clear sample.
Updated July 19, 2026 · Florida beach program (EPA BEACON)
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Know before you get in at 4TH AVENUE SOUTH BEACH.
Get an alert the day a bacteria or algae advisory goes up.
What's in the water at 4TH AVENUE SOUTH BEACH right now
As of July 19, 2026, 4TH AVENUE SOUTH BEACH in Collier County, Florida carries a swim caution. Blue-green algae are not currently monitored at this water. No fecal-bacteria advisory is posted (state beach program). Rainfall over the past week totaled 3.3 in, which can wash bacteria and nutrients into the water.
Blue-green algae at 4TH AVENUE SOUTH BEACH
4TH AVENUE SOUTH BEACH is a lake in Collier County, Florida. Blue-green algae are not currently monitored at this water.
Blue-green algae (cyanobacteria) blooms are most common from midsummer into early fall, when the water is warm, calm, and rich in nutrients from runoff. They can produce toxins that make people sick and can be rapidly fatal to dogs, so skip water that looks green, scummy, or like spilled paint, and keep children and pets out of it.
Frequently asked: swimming in 4TH AVENUE SOUTH BEACH
- Is it safe to swim in 4TH AVENUE SOUTH BEACH right now?
- 4TH AVENUE SOUTH BEACH carries a swim caution today. Blue-green algae are not currently monitored at this water. Conditions can change quickly with wind, heat, and rain, so check the posted signs and look at the water before you get in.
- Does 4TH AVENUE SOUTH BEACH have blue-green algae (cyanobacteria)?
- Blue-green algae are not currently monitored at 4TH AVENUE SOUTH BEACH. Watch for green, blue-green, or paint-like scum and avoid the water if you see it.
- Can dogs swim in 4TH AVENUE SOUTH BEACH?
- No bloom is detected at 4TH AVENUE SOUTH BEACH today, but dogs are much more vulnerable to blue-green algae than people, and blooms can form within hours. Always keep dogs away from water that looks green, scummy, or discolored, and rinse them off after swimming.
- How many Florida lakes and beaches have swim advisories today?
- Today, 97 Florida waters are under a swim advisory and 330 more warrant caution, out of 779 monitored waters SwimZone tracks in the state.
- How is 4TH AVENUE SOUTH BEACH's water quality measured?
- SwimZone builds this read from EPA CyAN satellite imagery for blue-green algae, official beach and fecal-bacteria advisories where a program monitors 4TH AVENUE SOUTH BEACH, and a recent-rainfall overlay, all refreshed daily. It was last updated July 19, 2026.