Is Lake Parsons safe to swim?

As of July 20, 2026, Lake Parsons in Neosho County, Kansas is not recommended for swimming. Satellite imagery measured 591,375 cells/mL of blue-green algae on July 19, 2026, above the 100,000 cells/mL advisory threshold. Rainfall over the past week totaled 0.9 in, which can wash bacteria and nutrients into the water.

How this read is built

Lake Parsons is a lake in Neosho County, Kansas covering about 1.3 sq mi, the 22nd-largest of the 28 lakes SwimZone monitors in Kansas. Satellite imagery measured 591,375 cells/mL of blue-green algae on July 19, 2026, above the 100,000 cells/mL advisory threshold.

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.

Over 7 summers of satellite monitoring since 2020, Lake Parsons has reached blue-green algae advisory levels in 7 of them, most recently in June 2026. This is a lake that blooms most summers. Its highest recorded reading was 1,596,111 cells/mL in August 2023.

Is it safe to swim in Lake Parsons right now?

Lake Parsons is not recommended for swimming today. Satellite imagery measured 591,375 cells/mL of blue-green algae on July 19, 2026, above the 100,000 cells/mL advisory threshold. Conditions can change quickly with wind, heat, and rain, so check the posted signs and look at the water before you get in.

Does Lake Parsons have blue-green algae (cyanobacteria)?

Yes. Satellite monitoring measured 591,375 cells/mL of blue-green algae (cyanobacteria) at Lake Parsons on July 19, 2026, above the 100,000 cells/mL advisory level. Avoid swimming and keep children and pets out of the water.

Can dogs swim in Lake Parsons?

No. Blue-green algae at Lake Parsons is above the safe-contact threshold (591,375 cells/mL on July 19, 2026). Cyanobacteria toxins can be rapidly fatal to dogs, which swallow it while swimming and lick it from their fur. Keep dogs out of the water and away from any scum along the shore.

How often does Lake Parsons have blue-green algae blooms?

Over 7 summers of satellite monitoring since 2020, Lake Parsons has reached blue-green algae advisory levels in 7 of them, most recently in June 2026. This is a lake that blooms most summers. Its highest recorded reading was 1,596,111 cells/mL in August 2023.

How many Kansas lakes and beaches are unsafe for swimming today?

Today, 10 Kansas waters are above a safe-contact threshold and 1 more warrant caution, out of 30 monitored waters SwimZone tracks in the state.

How is Lake Parsons'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 Lake Parsons, and a recent-rainfall overlay, all refreshed daily. It was last updated July 20, 2026.