Is Apple Canyon Lake safe to swim?

As of July 20, 2026, Apple Canyon Lake in Jo Daviess County, Illinois is not recommended for swimming. Satellite imagery measured 1,103,832 cells/mL of blue-green algae on July 19, 2026, above the 100,000 cells/mL advisory threshold. Rainfall over the past week totaled 0.0 in, which can wash bacteria and nutrients into the water.

How this read is built

Apple Canyon Lake is a lake in Jo Daviess County, Illinois covering about 0.6 sq mi, the 61st-largest of the 75 lakes SwimZone monitors in Illinois. Satellite imagery measured 1,103,832 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.

Is it safe to swim in Apple Canyon Lake right now?

Apple Canyon Lake is not recommended for swimming today. Satellite imagery measured 1,103,832 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 Apple Canyon Lake have blue-green algae (cyanobacteria)?

Yes. Satellite monitoring measured 1,103,832 cells/mL of blue-green algae (cyanobacteria) at Apple Canyon Lake 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 Apple Canyon Lake?

No. Blue-green algae at Apple Canyon Lake is above the safe-contact threshold (1,103,832 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 many Illinois lakes and beaches are unsafe for swimming today?

Today, 53 Illinois waters are above a safe-contact threshold and 7 more warrant caution, out of 138 monitored waters SwimZone tracks in the state.

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