Monroe County · Florida Keys · Atlantic Coast
Sombrero Beach Water Quality
Water quality is GOOD — Safe for swimming
The most recent test at Sombrero Beach showed enterococcus bacteria levels of 15 CFU/100mL, which is well within the safe range (35.4 or below CFU/100mL). Conditions are considered safe for swimming and water activities.
Historical Risk Rating
Sombrero Beach has an excellent track record. Only 0% of tests in the last 12 months returned poor results.
Water Quality History — Last 12 Months
Values in CFU/100mL. Green = Good (≤35.4), Yellow = Moderate (35.5–70.4), Red = Poor (≥70.5)
Swimming After Rain
Rainfall can wash bacteria, fertilizers, and other pollutants into the ocean through stormwater runoff. The Florida DOH recommends waiting at least 72 hours after heavy rain before swimming, especially near inlets, canals, and river mouths. If it has rained recently in the Monroe County area, use extra caution.
About Sombrero Beach
A popular public beach in Marathon with calm waters, palm trees, and picnic facilities — one of the best free beaches in the Florida Keys.
Nearby Beaches
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Disclaimer: Water quality data is sourced from the Florida Department of Health Healthy Beaches Program. Conditions can change rapidly. This website provides informational estimates only — always check with Florida DOH for official, real-time beach conditions. Safe to Swim Florida is an independent project and is not affiliated with any government agency.