Map of Ozone Monitors and Hourly Data
All of the online hourly Ozone data on this site will be updated on an hourly basis at half past each hour (24 hours a day) during the Ozone Season.
Online Seasonal Ozone Data is updated as it is Quality Assured.
| Breakpoints for the EPA's AQI (Air Quality Index) | ||
|---|---|---|
AQI Category  |
8 Hour O3 Breakpoint | 1 Hour O3 Breakpoint |
| Good | 0 to 64 | - |
| Moderate | 65 to 84 | - |
| Unhealthy for Sensitive Groups | 85 to 104 | 125 - 164 |
| Unhealthy | 105 to 124 | 165 to 204 |
| Very Unhealthy | 125 to 374 | 205 to 404 |
EPA AIR NOW Midwest Ozone Maps
