Greenfield, MA
Long-term air quality
What this page tells you
This page combines annual PM2.5, unhealthy days, 5-year trend, and data coverage so you can compare long-term air quality, not just today's reading.
Greenfield, MA air quality summary: Greenfield, MA, maintains a clean air score of 84 and a grade of B. The annual PM2.5 mean is 5.9, reflecting a healthy long-term environment. Greenfield records an annual PM2.5 mean of 5.9, which is a moderate level for long-term exposure. Long-term air quality in Greenfield has been worsening over recent years.
Clean Air Score
A score of 84 and a grade of B indicate that Greenfield enjoys relatively clean air with few interruptions. This grade reflects a stable environment that is suitable for residents focused on long-term air quality.
🏡 What This Means for Buying
Greenfield's air quality is a positive attribute for those considering long-term residency in the area. The consistent B grade serves as a reliable indicator of healthy atmospheric conditions.
Indoor Air Quality in Greenfield, MA
Outdoor pollution can still affect indoor air when windows are open, filtration is weak, or wildfire smoke moves in.
How to react when today's AQI changes
Use the AQI bands below to decide whether to open windows, run an air purifier, or stay indoors when pollution spikes in Greenfield.
AQI 0-50
GoodOpen windows: Open windows if you want fresh air.
Air purifier: No purifier needed for most homes.
Indoor activity: Normal indoor activity is fine.
AQI 51-100
ModerateOpen windows: Sensitive groups should limit open-window time.
Air purifier: Use fans or filtration if dust or pollen is bothering you.
Indoor activity: Most people can stay active indoors.
AQI 101-150
Unhealthy for Sensitive GroupsOpen windows: Keep windows closed.
Air purifier: Run a HEPA purifier in the main room and bedroom.
Indoor activity: Sensitive groups should reduce outdoor exposure.
AQI 151+
UnhealthyOpen windows: Keep windows and doors closed.
Air purifier: Run HEPA continuously and seal obvious drafts.
Indoor activity: Stay indoors as much as possible; use an N95 if you must go out.
Common indoor air concerns in Greenfield:
- Seasonal pollen and dust mite allergens
- VOCs from household products
Recommended action: If today's AQI reaches 101 or higher, close windows and run HEPA filtration before indoor air starts to feel smoky or stale.
Top Products for Greenfield Homes:
🩺 My Health Risk Assessment
See how Greenfield's air quality affects you and your family specifically.
Health Advice
Enjoy the outdoors! Air quality is great.
Add Greenfield Air Quality to your site
Perfect for local news, real estate blogs, and community pages.
</> Create Free Widget🏡 Property Value Impact Analysis
Between 2019 and 2024, Greenfield's air quality worsened by 0.9 μg/m³. Based on NBER studies, this change correlates with a estimated 3.6% decrease in relative property value retention.
Cleaner Alternatives in NH
Why Greenfield earned a 84
Raw inputs, scoring weights, and data coverage for this city.
Best Time to Run
Find the cleanest hours for your run today.
Cycling Forecast
Avoid pollution spikes on your next ride.
📅 Past 30 Days Trend
Real-time daily PM2.5 AQI
🌸 Pollen Outlook
Current Seasonal Forecast
How it worksBased on current seasonal forecast data. Not a long-term pollution rating or relocation score.
Score Breakdown
| Component | Weight | Score Contribution |
|---|---|---|
| Annual Air Quality | 40% | 87 |
| Unhealthy Days | 25% | 100 |
| 5-Year Trend | 20% | 45.5 |
| Seasonal Variability | 10% | 92 |
| Extreme Events | 5% | 100 |
Explore More Air Quality Data
Frequently Asked Questions
About This Data
Data Sources
Historical air quality mapping and scoring are based completely on official U.S. Environmental Protection Agency (EPA) AirNow API data. 5-day AQI forecasts are provided by WAQI.
Methodology
Our Clean Air Score (0-100) is a proprietary algorithm that weighs multiple factors:
- Annual PM2.5 averages (40%)
- Frequency of unhealthy days (25%)
- 5-year pollution trends (20%)
- Seasonal variability and extreme events (15%)
Updates & Accuracy
Real-time data is updated hourly. Historical aggregate scores are recalculated monthly to reflect the latest trends. While we strive for accuracy, sensor maintenance and local conditions can affect individual readings.
Practical Advice
When AQI > 100: Sensitive groups (children, elderly, asthmatics) should limit prolonged outdoor exertion.
When AQI > 150: Everyone should avoid outdoor exercise and keep windows closed.
More Cities in NH
Similar Rankings Nationwide
Greenfield Air Quality FAQs
Is Greenfield a good fit for people who care about long-term air quality?
Greenfield is a favorable location, with a clean air score of 84 and a grade of B. The annual PM2.5 mean of 5.9 indicates a healthy long-term environment for most residents.
What is the frequency of unhealthy air in Greenfield?
Greenfield reports 0% unhealthy days, indicating that acute pollution events are extremely rare. This performance supports the city's B grade and healthy annual PM2.5 mean.
Is air quality in Greenfield improving or getting worse over time?
Air quality in Greenfield is currently worsening. Residents should note that particulate levels have trended slightly higher in recent years.
Does air quality vary within Greenfield?
Particulate levels can fluctuate within the city based on local traffic and industrial patterns. While the overall average is good, specific neighborhoods may experience slight variations.