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Bucyrus, OH Air Quality

EPA monitor data through 2010 · Updated September 02, 2026 · Methods

This area's record ends with 2010 (a partial year: 284 days of monitoring data): EPA's air quality files carry no 2011–2025 data for it, usually because local monitors stopped reporting. This page is current with the data that exists.

In 2010, Bucyrus, OH recorded 1 days above an Air Quality Index of 100, the level at which EPA begins warning sensitive groups, out of 284 days with monitoring data. The rest of the year was 235 Good days and 48 Moderate days. Most of the bad days were driven by ozone. Under the AQI rules that applied before 2013, the same air would have scored 0 days. Since 2000, unhealthy days are 100% lower on a consistent definition.

Unhealthy days by year, scored two ways

EPA changed what an AQI of 100 means in 2013 and again in 2015, so a count published before those changes is not comparable to one published after. Each panel below applies a single fixed rulebook to every year, so each is internally consistent. Why this matters.

What 2010 looked like

Median AQI 41 · 90th-percentile AQI 63 · worst day 112. Scored under current rules, out of 284 days with an AQI.

What drove the unhealthy days

Of the 1 days above 100 in 2010, 1 were driven by ozone and 0 by fine particles. The two behave differently. Ozone peaks on hot sunny afternoons; fine particles now spike mainly with wildfire smoke. In the eastern United States, ozone has stopped responding to emission cuts: nitrogen oxide emissions kept falling after 2014 and ambient ozone barely moved.

Day-level detail is available for 2025; this area's latest year of data is 2010.

Statewide context

Bucyrus, OH sits in Ohio.

Days in each air quality category, by year

How many days fell in each AQI category, for every year with an AQI on record. Categories are scored under EPA's current breakpoints. A year with fewer than 300 days is marked, because a short year lowers every count for reasons that have nothing to do with the air.

Good is AQI 0–50, Moderate 51–100, Unhealthy for sensitive groups 101–150. “Unhealthy or worse” combines the Unhealthy, Very Unhealthy and Hazardous categories, which are shown together because most areas record too few of each to report separately. The four columns sum to the last one by construction. These counts exclude sulphur dioxide, following EPA, which drops SO₂ from county and metro summaries because it is too localized to describe a whole area.

The full series

The same years scored two ways, with the pollutant that drove the days above 100. EPA's files record which pollutant set each day's AQI; they do not attribute days to wildfire smoke, so no column here claims to.

Sources

• EPA AirData daily monitor files, recomputed under both breakpoint tables. Methods and validation.
• Download the full dataset for every state and metro.