Cary, Illinois Air Quality
Cary has a median AQI of 43, earning an air quality grade of A- — excellent air quality that ranks better than 39% of US cities. Air quality has remained relatively stable over the past decade. Ground-level ozone is the primary concern, typically peaking on warm sunny days due to vehicle and industrial emissions. In 2025, Cary recorded 180 good air quality days (66% of monitored days) and 12 unhealthy days.
Population: 17,923 • County: McHenry
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Quick Facts
| Current AQI | 13 — Good |
| Air Quality Grade | A- |
| Median AQI (2025) | 43 |
| vs. U.S. Cities | Better than 39% |
| Primary Pollutant | Ozone |
| Unhealthy Days/Year | 12 |
| 10-Year Trend | → Stable |
| Data Source | EPA AirNow |
Health Recommendation
Air quality is satisfactory, and air pollution poses little or no risk.
It's a great day to be active outside!
5-Day AQI Forecast
Last 30 Days
Current Pollutant Levels
Real-time data from EPA AirNow
AQI Trend (10 Years)
Air Quality Days by Year
2025 Air Quality Summary
Primary Pollutant Days (2025)
Days when each pollutant was the primary driver of AQI. Learn about pollutants →
Frequently Asked Questions About Cary Air Quality
What is the air quality in Cary today?
The current AQI in Cary is 13, which is rated "Good". Air quality is satisfactory, and air pollution poses little or no risk.
Is air quality in Cary getting better or worse?
Air quality in Cary has remained relatively stable over the past decade, with a median AQI of around 43.
What is the most common air pollutant in Cary?
Ozone is the primary air pollutant in Cary, responsible for the most air quality-impacted days in 2025. Ground-level ozone forms when sunlight reacts with vehicle and industrial emissions on warm days.
How many unhealthy air days does Cary have per year?
In 2025, Cary had 12 days when air quality was unhealthy or unhealthy for sensitive groups (AQI above 100). There were 180 good days and 80 moderate days out of 272 days monitored.
What air quality grade does Cary receive?
Cary receives an air quality grade of A-, placing it better than 39% of US cities. This grade is based on a median AQI of 43 for 2025, derived from EPA monitoring data.
Air Quality Grade
Better than 39% of US cities
Nearby Cities
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National Rankings
See how Cary compares to every other US city by air quality.
Best Air Quality Cities →All city rankingsRecommended Air Purifiers for Cary
Based on your area's air quality (median AQI: 43), we recommend these air purifiers to help protect your health indoors.
RabbitAir MinusA2
Stylish wall-mountable design with customizable artwork panels.
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Other Great Options
Molekule Air Pro
Commercial-grade with patented PECO technology for destroying pollutants.
Blueair Blue Pure 211+
High performance for large rooms with simple operation.
Dyson Pure Cool TP04
Premium all-in-one air purifier and fan with advanced features.
Not sure which air purifier is right for you?
Learn more about different types of air purifiers and how to choose the best one for your needs.
Read our complete buying guide →