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Ohio Air Quality

Canton and Massillon is the worst air in Ohio right now at an index of 57, which is Moderate, from fine particles (PM2.5). AirNow carries 8 reporting areas in the state. No air quality alert is in force.

Reporting areas: 8
Worst index now: 57
Alerts in force: 0
Towns under smoke: Unavailable

Radar

Reflectivity now over Ohio. Open it to see the particulate forecast on the map.

Open the live radar with the particulate forecast

Radar mosaic and map layers from NOAA MRMS and NOAA National Air Quality Forecast Capability. Boundaries from the Iowa Environmental Mesonet.

Alerts in force

An Air Quality Alert is issued by the National Weather Service on behalf of a state or local agency when pollution is expected to reach a level that harms health. An Air Stagnation Advisory means the air will not move enough to clear what is already in it.

None are in force in Ohio right now. All Ohio warnings.

By city, now and the days ahead8

Every AirNow reporting area in Ohio: what its monitors measured this hour, and what the state or local agency that forecasts for it expects today and tomorrow. Each area links to the nearest town’s page.

Reporting area	Now	Category now	Today	Tomorrow	Pollutant
Canton and Massillon	57	Moderate	Moderate	Good	PM2.5
Dayton	54	Moderate	Moderate	Moderate	PM2.5
Lima	54	Moderate	Not forecast	Not forecast	PM2.5
Toledo	54	Moderate	Not forecast	Not forecast	PM2.5
Columbus	52	Moderate	Good	Good	PM2.5
Cleveland-Akron-Lorain	48	Good	Moderate	Not forecast	PM2.5
Cincinnati	39	Good	Moderate	Good	PM2.5
Youngstown	37	Good	Good	Good	PM2.5

The forecaster’s discussion

Written by MORPC for Columbus and filed with AirNow.

Saturday, September 19: Light southeasterly morning winds will transport pollutants into the Columbus region. In addition, periods of sunshine will aid ozone production. However, afternoon showers will enhance mixing and limit ozone formation, keeping AQI levels Good. Sunday, September 20: As a surface low pressure system moves across the Columbus region, atmospheric mixing and dispersion will increase. Additionally, clouds and rain showers will inhibit ozone formation. However, periods of westerly winds will bring regional pollutants into the area, yielding high-Good AQI levels. Monday through Wednesday, northeasterly to easterly winds will transport clean, cool air into central Ohio, while mostly cloudy skies and showers will limit ozone development. Therefore, AQI levels will remain Good on all three days. Thursday, as a low pressure system stalls over southwest Ohio, southeasterly winds will carry regional pollutants into central Ohio. However, clouds and showers will continue to inhibit ozone formation, and pollutant carryover from previous days will be low. Therefore, AQI levels will be high-Good.

Smoke

NOAA’s Hazard Mapping System smoke analysis could not be read just now.

Smoke on the radar over Ohio

What this means

The index runs from 0 to 500. Good is 0 to 50, Moderate to 100, Unhealthy for Sensitive Groups to 150, Unhealthy to 200, Very Unhealthy to 300, and Hazardous above that. The figure reported for a place is the highest index among the pollutants measured there, and the pollutant that produced it is named beside it.

What these numbers are. An index beside a monitor’s name is a measurement, published hourly by AirNow and preliminary until the operating agency certifies it. A category for today or tomorrow is a state or local agency forecaster’s own forecast for a reporting area. An hourly index is NOAA’s air quality model on a five-kilometer grid, not a reading from any instrument. Where a town has no monitor within reach, only the model figures appear, and the page says so.

Towns

Air quality for any town in Ohio: what is measured nearby, the category forecast for today and tomorrow, and NOAA’s model hour by hour. Largest first.

487 smaller towns

Smaller places have pages too; search for one on the air quality landing page.

Sources

Observations and daily forecasts from AirNow, the US Environmental Protection Agency’s program with NOAA, the National Park Service, NASA, tribal, state and local agencies. Hourly forecasts from NOAA’s National Air Quality Forecast Capability. Smoke analysis from NOAA’s Hazard Mapping System. Alerts from the National Weather Service. Index categories and breakpoints are EPA’s, as revised in 2024.