Norfeld Colony, South Dakota Air Quality
Norfeld Colony has a median AQI of 48, earning an air quality grade of B+ — good air quality that ranks better than 17% of US cities. Air quality has been trending worse over the past decade, a concern for local residents and health officials. Particulate matter (PM2.5) is the primary concern, often linked to vehicle traffic, industrial activity, and wildfire smoke. In 2025, Norfeld Colony recorded 96 good air quality days (53% of monitored days) and 3 unhealthy days.
0Current AQI
Quick Facts
| Current AQI | 23 — Good |
| Air Quality Grade | B+ |
| Median AQI (2025) | 48 |
| vs. U.S. Cities | Better than 17% |
| Primary Pollutant | PM2.5 |
| Unhealthy Days/Year | 3 |
| 10-Year Trend | ↓ Worsening |
| 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 Norfeld Colony is sourced from the Research Farm monitoring area, located approximately 13 miles from city center. This EPA-certified station continuously tracks particulate matter (PM2.5), the primary driver of air quality alerts in this area.
Norfeld Colony typically sees its worst air quality during summer afternoons when heat and sunlight drive ground-level ozone formation from vehicle and industrial emissions. Morning readings are generally 15–25 points lower than afternoon peaks. Outdoor activity is best planned for early morning on high-ozone days.
AQI Trend (10 Years)
Air Quality Days by Year
Norfeld Colony Median AQI by Year
Annual EPA air quality data for Norfeld Colony — median AQI, day-category breakdown, and primary pollutant per year.
| Year | Median AQI | Good Days | Unhealthy Days | Max AQI | Primary Pollutant |
|---|---|---|---|---|---|
| 2025 | 48 | 96 | 3 | 154 | PM2.5 |
| 2024 | 36 | 292 | 2 | 111 | Ozone |
| 2023 | 42 | 274 | 7 | 162 | Ozone |
| 2022 | 36 | 320 | — | 87 | Ozone |
| 2021 | 39 | 270 | 8 | 236 | Ozone |
| 2020 | 39 | 305 | — | 87 | Ozone |
| 2019 | 43 | 273 | 5 | 126 | Ozone |
| 2018 | 38 | 297 | 1 | 101 | Ozone |
| 2017 | 36 | 311 | — | 90 | Ozone |
| 2016 | 35 | 329 | 1 | 101 | Ozone |
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 Norfeld Colony Air Quality
What is the air quality in Norfeld Colony today?
The current AQI in Norfeld Colony is 23, 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 Norfeld Colony getting better or worse?
Air quality in Norfeld Colony has been worsening. The median AQI has risen 13 points (from 35 in 2016 to 48 in 2025), a concern for local health officials.
What is the most common air pollutant in Norfeld Colony?
PM2.5 is the primary air pollutant in Norfeld Colony, responsible for 136 days (75% of monitored days) in 2025. Particulate matter originates from vehicle exhaust, wildfires, construction, and industrial activity.
How many unhealthy air days does Norfeld Colony have per year?
In 2025, Norfeld Colony recorded 53% good air quality days (96 days) out of 181 monitored days. There were 2 Unhealthy for Sensitive Groups days and 1 Unhealthy days (AQI above 100). The highest single-day AQI recorded was 154.
What air quality grade does Norfeld Colony receive?
Norfeld Colony receives an air quality grade of B+, placing it better than 17% of US cities. This is based on a median AQI of 48 in 2025, with 96 good air quality days. The EPA monitors air quality in this area continuously using certified monitoring stations.
Air Quality Grade
Better than 17% of US cities
Nearby Cities
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National Rankings
See how Norfeld Colony compares to every other US city by air quality.
Best Air Quality Cities →All city rankingsRecommended Air Purifiers for Norfeld Colony
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