St. Joseph, Missouri Air Quality
St. Joseph has a median AQI of 39, earning an air quality grade of A — excellent air quality that ranks better than 65% of US cities. Air quality has been improving steadily over the past decade, a positive sign for residents. Particulate matter (PM2.5) is the primary concern, often linked to vehicle traffic, industrial activity, and wildfire smoke. In 2025, St. Joseph recorded 95 good air quality days (64% of monitored days).
Population: 73,256 • County: Buchanan
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Quick Facts
| Current AQI | 18 — Good |
| Air Quality Grade | A |
| Median AQI (2025) | 39 |
| vs. U.S. Cities | Better than 65% |
| Primary Pollutant | PM2.5 |
| Unhealthy Days/Year | 0 |
| 10-Year Trend | ↑ Improving |
| 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 St. Joseph Air Quality
What is the air quality in St. Joseph today?
The current AQI in St. Joseph is 18, which is rated "Good". Air quality is satisfactory, and air pollution poses little or no risk.
Is air quality in St. Joseph getting better or worse?
Air quality in St. Joseph has been improving over the past decade. The median AQI dropped from 44 in 2016 to 39 in 2025.
What is the most common air pollutant in St. Joseph?
PM2.5 is the primary air pollutant in St. Joseph, responsible for the most air quality-impacted days in 2025. Particulate matter can originate from vehicle exhaust, wildfires, and industrial emissions.
How many unhealthy air days does St. Joseph have per year?
In 2025, St. Joseph had 0 days when air quality was unhealthy or unhealthy for sensitive groups (AQI above 100). There were 95 good days and 52 moderate days out of 148 days monitored.
What air quality grade does St. Joseph receive?
St. Joseph receives an air quality grade of A, placing it better than 65% of US cities. This grade is based on a median AQI of 39 for 2025, derived from EPA monitoring data.
Air Quality Grade
Better than 65% of US cities
Nearby Cities
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National Rankings
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Best Air Quality Cities →All city rankingsRecommended Air Purifiers for St. Joseph
Based on your area's air quality (median AQI: 39), we recommend these air purifiers to help protect your health indoors.
Blueair Blue Pure 211+
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Honeywell HPA300
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Premium all-in-one air purifier and fan with advanced features.
Molekule Air Pro
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