Downey, Idaho Air Quality
Downey has a median AQI of 31, earning an air quality grade of A — excellent air quality that ranks better than 87% of US cities. Air quality has been improving steadily over the past decade, a positive sign for residents. Particulate matter (PM10) is the primary concern, often linked to vehicle traffic, industrial activity, and wildfire smoke. In 2025, Downey recorded 278 good air quality days (91% of monitored days) and 1 unhealthy days.
Population: 803 • County: Bannock
Current AQI
Quick Facts
| Current AQI | 10 — Good |
| Air Quality Grade | A |
| Median AQI (2025) | 31 |
| vs. U.S. Cities | Better than 87% |
| Primary Pollutant | PM10 |
| Unhealthy Days/Year | 1 |
| 10-Year Trend | ↑ Improving |
| Data Source | EPA AQS (historical) · AirNow (live) |
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 90 Days
Current Pollutant Levels
Real-time data from EPA AirNow
Local Air Quality Context
Air quality data for Downey is sourced from the Shoshone Bannock Tribes monitoring area, located approximately 20 miles from city center. This EPA-certified station continuously tracks particulate matter (PM10), the primary driver of air quality alerts in this area.
Wildfire smoke is a significant factor in Downey's air quality, with regional fires capable of pushing AQI from Good to Unhealthy within hours during fire season (typically July through October). On smoke-impacted days, staying indoors with windows closed and running an air purifier with a HEPA filter is the most effective protection.
AQI Trend (10 Years)
Air Quality Days by Year
Downey Median AQI by Year
Annual EPA air quality data for Downey — median AQI, day-category breakdown, and primary pollutant per year.
| Year | Median AQI | Good Days | Unhealthy Days | Max AQI | Primary Pollutant |
|---|---|---|---|---|---|
| 2025 | 31 | 278 | 1 | 111 | PM10 |
| 2024 | 39 | 286 | 2 | 104 | PM2.5 |
| 2023 | 41 | 293 | 33 | 557 | Ozone |
| 2022 | 40 | 270 | 2 | 140 | PM2.5 |
| 2021 | 44 | 245 | 8 | 155 | PM2.5 |
| 2020 | 38 | 284 | 6 | 165 | PM2.5 |
| 2019 | 24 | 330 | — | 64 | PM2.5 |
| 2018 | 29 | 298 | 4 | 174 | PM2.5 |
| 2017 | 38 | 225 | 6 | 168 | PM2.5 |
| 2016 | 36 | 266 | — | 86 | PM2.5 |
Source: EPA Air Quality System (AQS) annual summaries. "Unhealthy Days" includes Unhealthy for Sensitive Groups, Unhealthy, Very Unhealthy, and Hazardous categories.
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 Downey Air Quality
What is the air quality in Downey today?
The current AQI in Downey is 10, rated "Good". Air quality is good — outdoor activity is safe for everyone today. Air quality is satisfactory, and air pollution poses little or no risk.
Is air quality in Downey getting better or worse?
Air quality in Downey has been improving. The median AQI has dropped 5 points (from 36 in 2016 to 31 in 2025), a positive trend for residents.
What is the most common air pollutant in Downey?
PM10 is the primary air pollutant in Downey, responsible for 163 days (54% of monitored days) in 2025. Particulate matter originates from vehicle exhaust, wildfires, construction, and industrial activity.
How many unhealthy air days does Downey have per year?
In 2025, Downey recorded 91% good air quality days (278 days) out of 304 monitored days. There were 1 Unhealthy for Sensitive Groups days and 0 Unhealthy days (AQI above 100). The highest single-day AQI recorded was 111.
What air quality grade does Downey receive?
Downey receives an air quality grade of A, placing it better than 87% of US cities. This is based on a median AQI of 31 in 2025, with 278 good air quality days. The EPA monitors air quality in this area continuously using certified monitoring stations.
Air Quality Grade
Better than 87% of US cities
Nearby Cities
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National Rankings
See how Downey compares to every other US city by air quality.
Best Air Quality Cities →All city rankingsRecommended Air Purifiers for Downey
Downey's primary pollutant is PM10 (coarse dust and pollen). Units with a washable pre-filter stage plus True HEPA handle the larger particles that drive most of this area's air quality days.
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