As sweltering heat and humidity grip the Hudson Valley, beachgoers in Rockland County have a reason to rejoice: Lake Welsh in Harriman State Park is back open for swimming.

The popular beach was closed last week due to a harmful algal bloom, or HAB, which can cause health problems for humans and animals. New York State Parks officials treated the water with algaecide, and after testing showed the water to be safe, the beach was reopened.

This is good news for those looking to cool off in the lake, as the beach was closed for most of the summer in 2022 due to a similar HAB.

"We have buoys in the water that can monitor for the harmful algal blooms" says Ed McGowan, of the New York State Parks Department of Recreation. "As these pigments increase, it's not something that we can see with our eyes, but the monitoring device can pick up and let us know it's coming. They also have ultrasound that is meant to kill the HABs around them, but that's more experimental at this stage."

Lake Welsh is open seven days a week, and health officials say they are constantly monitoring the water to make sure it's safe.

While Lake Welsh is now open, some beaches in Putnam County remain closed due to harmful algal blooms.