Beach · Bayfield County · WI
Is Sioux River Beach South safe to swim?
No advisory or algae bloom reported for this water today.
Updated July 19, 2026 · Wisconsin beach program (EPA BEACON)
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What's in the water at Sioux River Beach South right now
As of July 19, 2026, Sioux River Beach South in Bayfield County, Wisconsin is clear to swim. 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 0.0 in, which can wash bacteria and nutrients into the water.
Blue-green algae at Sioux River Beach South
Sioux River Beach South is a lake in Bayfield County, Wisconsin. 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 Sioux River Beach South
- Is it safe to swim in Sioux River Beach South right now?
- Sioux River Beach South is clear to swim 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 Sioux River Beach South have blue-green algae (cyanobacteria)?
- Blue-green algae are not currently monitored at Sioux River Beach South. Watch for green, blue-green, or paint-like scum and avoid the water if you see it.
- Can dogs swim in Sioux River Beach South?
- No bloom is detected at Sioux River Beach South 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 Wisconsin lakes and beaches have swim advisories today?
- Today, 91 Wisconsin waters are under a swim advisory and 11 more warrant caution, out of 564 monitored waters SwimZone tracks in the state.
- How is Sioux River Beach South'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 Sioux River Beach South, and a recent-rainfall overlay, all refreshed daily. It was last updated July 19, 2026.