Lake · Mahoning County · OH
Is Pine Lake safe to swim?
Blue-green algae is above the safe-contact threshold.
Updated July 22, 2026 · EPA CyAN satellite
No bacteria advisory or sampling for this water.
Cyanobacteria 662,435 cells/mL (satellite, 7-day max), imaged 2026-07-21.
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There's an advisory on Pine Lake right now.
Get an alert the day it clears, and every time a new one goes up.
What's in the water at Pine Lake right now
As of July 22, 2026, Pine Lake in Mahoning County, Ohio is not recommended for swimming. Satellite imagery measured 662,435 cells/mL of blue-green algae on July 21, 2026, above the 100,000 cells/mL advisory threshold. Rainfall over the past week totaled 2.0 in, which can wash bacteria and nutrients into the water.
Blue-green algae at Pine Lake
Pine Lake is a lake in Mahoning County, Ohio. Satellite imagery measured 662,435 cells/mL of blue-green algae on July 21, 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.
Bloom history at Pine Lake
From EPA CyAN's satellite archive
Each bar is that summer's peak satellite reading (log scale). The red cap is the part above the advisory level.
Over 7 summers of satellite monitoring since 2020, Pine Lake has reached blue-green algae advisory levels in 6 of them, most recently in August 2025. This is a lake that blooms most summers. Its highest recorded reading was 2,585,253 cells/mL in September 2023.
When to swim at Pine Lake
It is currently peak season for blue-green algae, when warm, calm water lets blooms form fastest. This lake has bloomed in most monitored summers (6 of 7), historically peaking around September. Early summer, before the water fully warms, has generally been the safer window here; check the current read before you go either way.
Frequently asked: swimming in Pine Lake
- Is it safe to swim in Pine Lake right now?
- Pine Lake is not recommended for swimming today. Satellite imagery measured 662,435 cells/mL of blue-green algae on July 21, 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 Pine Lake have blue-green algae (cyanobacteria)?
- Yes. Satellite monitoring measured 662,435 cells/mL of blue-green algae (cyanobacteria) at Pine Lake on July 21, 2026, above the 100,000 cells/mL advisory level. Avoid swimming and keep children and pets out of the water.
- Can dogs swim in Pine Lake?
- No. Blue-green algae at Pine Lake is above the safe-contact threshold (662,435 cells/mL on July 21, 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 Pine Lake have blue-green algae blooms?
- Over 7 summers of satellite monitoring since 2020, Pine Lake has reached blue-green algae advisory levels in 6 of them, most recently in August 2025. This is a lake that blooms most summers. Its highest recorded reading was 2,585,253 cells/mL in September 2023.
- How many Ohio lakes and beaches are unsafe for swimming today?
- Today, 33 Ohio waters are above a safe-contact threshold and 32 more warrant caution, out of 101 monitored waters SwimZone tracks in the state.
- How is Pine 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 Pine Lake, and a recent-rainfall overlay, all refreshed daily. It was last updated July 22, 2026.
Before you swim: the basics
Swim spots near Pine Lake
All Ohio →Of the 6 monitored waters nearest Pine Lake, 5 are flagged today.
| Water | Distance | Today | Algae read | Sampled |
|---|---|---|---|---|
| Evans LakeLake · Mahoning County | 3.9 mi | Clear to swim | None detected | Jul 21 |
| Guilford LakeLake · Columbiana County | 15 mi | Advisory | 1,465,895 cells/mL | Jul 21 |
| Meander Creek ReservoirReservoir · Mahoning County | 16 mi | Advisory | 325,944 cells/mL | Jul 21 |
| Berlin LakeLake · Portage County | 21 mi | Advisory | 527,938 cells/mL | Jul 21 |
| Lake MiltonLake · Mahoning County | 22 mi | Advisory | 354,898 cells/mL | Jul 21 |
| Deer Creek ReservoirReservoir · Stark County | 26 mi | Advisory | 1,103,832 cells/mL | Jul 21 |