Kailua Bay is a saltwater beach in Hawaii County, Hawaii. Across 47 bacteria samples collected between 2021 and 2024 at nearby monitoring stations, it earns a Beach Safety Grade of B — Good.
About 6% of samples at Kailua Bay exceeded the EPA Beach Action Value of 104 CFU/100 mL for Enterococcus — the threshold at which water managers typically post a swimming advisory. In practice that means the safe-swimming limit was sometimes crossed here over the monitored period. Bacteria samples rarely exceed the safe-swimming threshold.
Kailua Bay was not under a swimming advisory in the most recent EPA snapshot. Conditions can change quickly after heavy rain or high runoff, so it's still worth checking the current advisory the day you go.