Very heavy rainfall in the last 48 hours (0.80 in) triggers the AACO preemptive no-swim advisory.
Raining now — live
How swim safety is determined
Safe to swim? Yep!
48-hour rainfall≤ 0.125 in
Heavy rain eventsNone in the last 72 hours
Bacteria (enterococci)≤ 25 (25% of EPA 104 limit)
Safe to swim? Yes... but not 100%
48-hour rainfall0.125–0.245 in
Heavy rain eventsNone in the last 72 hours
Bacteria (enterococci)26–50 (26–49% of EPA 104 limit)
Safe to swim? Questionable...
48-hour rainfall0.245–0.494 in
Heavy rain eventsPeak > 0.125 in/hr, ended between 48 and 72 hours ago
Bacteria (enterococci)51–103 (50–99% of EPA 104 limit)
Safe to swim? Nope!
48-hour rainfall> 0.494 in (AACO preemptive advisory at ≥ 0.5 in)
Heavy rain eventsPeak > 0.125 in/hr, ended within the last 48 hours
Bacteria (enterococci)≥ 104 (100%+ of EPA limit)
Heavy rain = any spell with a rolling 60-minute peak above 0.125 in/hr.
Bacteria from the latest AACO sample at Arden on the Severn at Oakview.
Samples collected after rain are marked with a rain icon but use the same thresholds.
Last 24 Hours0.580 in
Last 48 Hours0.797 in
Last 72 Hours0.824 in
Active Rain
Started Sep 22, 5:37 PM
· 0.163 in
· peak 0.091 in/hr