South Portland, ME
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.
South Portland, ME air quality summary: South Portland, ME, maintains a clean air score of 85.2 and an air quality grade of A, reflecting its long-term atmospheric profile. The city's annual PM2.5 mean of 5.7 µg/m³ indicates moderate particulate exposure for residents. South Portland has an annual PM2.5 mean of 5.7 µg/m³, which is a key indicator of long-term fine particulate exposure. The long-term air quality trend in South Portland is showing a positive trajectory with improving conditions in recent years.
Clean Air Score
The clean air score of 85.2 and grade of A are based on multi-year particulate matter trends analyzed for South Portland. These metrics provide a standardized way to evaluate long-term exposure risks in the local environment.
🏡 What This Means for Buying
Prospective residents should evaluate South Portland's air quality as part of a comprehensive assessment of local environmental factors. Long-term air quality should be treated as one factor in a broader relocation or housing decision.
Indoor Air Quality in South Portland, ME
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 South Portland.
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 South Portland:
- 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 South Portland Homes:
🩺 My Health Risk Assessment
See how South Portland's air quality affects you and your family specifically.
Health Advice
Enjoy the outdoors! Air quality is great.
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</> Create Free Widget🏡 Property Value Impact Analysis
Between 2019 and 2024, South Portland's air quality improved by 3 μg/m³. Based on NBER studies, this change correlates with a estimated 12% increase in relative property value retention.
Cleaner Alternatives in ME
Why South Portland earned a 85.2
Raw inputs, scoring weights, and data coverage for this city.
Best Time to Run
Find the cleanest hours for your run today.
Cycling Forecast
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📅 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% | 90.3 |
| Unhealthy Days | 25% | 100 |
| 5-Year Trend | 20% | 65 |
| Seasonal Variability | 10% | 90.5 |
| 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.
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South Portland Air Quality FAQs
Is South Portland a good fit for people who care about long-term air quality?
South Portland presents a clean air score of 85.2 and a grade of A for long-term atmospheric health. With an annual PM2.5 mean of 5.7 µg/m³, the city provides a data-backed perspective for air quality-conscious individuals.
What is the frequency of unhealthy air or long-term pollution exposure in South Portland?
The percentage of days with unhealthy air in South Portland is 0%, contributing to its overall grade of A. This metric reflects the frequency of acute pollution spikes relative to the city's annual PM2.5 mean of 5.7 µg/m³.
Is air quality in South Portland improving or getting worse over time?
In South Portland, the long-term trend for air quality is categorized as improving. Data completeness for this analysis is 100.0%, providing a solid foundation for this trend assessment.
Does air quality vary within the city of South Portland?
While South Portland has a general air quality profile, conditions can vary locally due to traffic patterns, industrial activity, and geography. Even without distinct neighborhood monitoring, residents may experience slight differences based on their specific location within the city.