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Severn, MD

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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.

Jump to indoor air guidance Read the formula
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Note: Severn does not have its own EPA monitor and that the page relies on the nearest monitor in Baltimore, 11.6 miles away.
📍 Homebuyer Guide 📊 Data Coverage: 99.5% 📅 2021-2025 Trends

Severn, MD air quality summary: Severn, MD receives a clean air score of 80.1 and a grade of B, indicating healthy long-term air quality. The city's annual mean for PM2.5 is 6.6 µg/m³. The annual mean concentration of PM2.5 in Severn is 6.6 µg/m³. Long-term air quality in Severn has been improving over recent years.

Clean Air Score

80
Grade B

A clean air score of 80.1 and a grade of B indicate that Severn has relatively low particulate exposure over time. These metrics suggest a favorable environmental profile for long-term residency.

🏡 What This Means for Buying

Air quality is a reliable positive consideration for those evaluating housing in Severn. The city's B grade represents a level of pollution that is considered moderate and acceptable.

Best time for outdoor visits: Check seasonal chart

Indoor Air Quality in Severn, MD

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 Severn.

AQI 0-50

Good

Open 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

Moderate

Open 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 Groups

Open 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+

Unhealthy

Open 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 Severn:

  • 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 Severn Homes:

Best HEPA Air Purifier for Severn Wildfire Smoke PM2.5 Indoor Air Quality Monitor Formaldehyde & VOC Detector
People also search: "indoor air quality in Severn, MD"

🩺 My Health Risk Assessment

See how Severn's air quality affects you and your family specifically.

Current Risk Level
Low Risk
🟢
💡

Health Advice

Enjoy the outdoors! Air quality is great.

Est. Annual "Risky Days" for you: ~0 days/year

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🏡 Property Value Impact Analysis

Estimated Impact (5-Year)
Positive Signal
+7.2% theoretical value retention

Between 2019 and 2024, Severn's air quality improved by 1.8 μg/m³. Based on NBER studies, this change correlates with a estimated 7.2% increase in relative property value retention.

* Methodology: Comparison based on National Bureau of Economic Research (NBER) Working Paper 15655 correlation between PM2.5 reduction and housing prices. This is a theoretical estimate for informational purposes only.
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Annual PM2.5
6.6 μg/m³
WHO Target: <5.0
Good Days
100.0 %
% days AQI < 100
5-Year Trend
Improving
↑ Improving
Long-term direction
Extreme Days
0 days/yr
Days AQI > 150 (Est.)

Why Severn earned a 80.1

Raw inputs, scoring weights, and data coverage for this city.

See full formula
Annual Air Quality
6.6 μg/m³
Component score 76.8 × 40% = 30.7 points
Unhealthy Days
0 days/yr est.
0% of days above AQI 100. Component score 100 × 25% = 25.0 points
5-Year Trend
Improving
Component score 59 × 20% = 11.8 points
Seasonal Variability
93.9
Higher means steadier month-to-month air. Weighted contribution: 9.4 points
Extreme Events
100
Captures severe pollution spikes. Weighted contribution: 5.0 points
Coverage & Monitoring
99.5%
Proxy monitor: Baltimore (11.6 miles away)
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Best Time to Run

Find the cleanest hours for your run today.
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Cycling Forecast

Avoid pollution spikes on your next ride.

📅 Past 30 Days Trend

Real-time daily PM2.5 AQI

Live Data

Score Breakdown

Component Weight Score Contribution
Annual Air Quality 40% 76.8
Unhealthy Days 25% 100
5-Year Trend 20% 59
Seasonal Variability 10% 93.9
Extreme Events 5% 100

Explore More Air Quality Data

View more cities in MD See how Severn compares nationally

Frequently Asked Questions

How often is this air quality data updated? Our historical trend models and annual rankings are updated regularly based on official EPA data to ensure reports reflect the latest available long-term trends.
What sources does CleanAirData use? We rely strictly on official U.S. Environmental Protection Agency (EPA) monitoring station data for all historical air quality scoring and reports.
Data sourced from U.S. Environmental Protection Agency (EPA) — See our methodology

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.

Data provided for informational purposes only. Always consult local health officials during extreme smoke or pollution events.

More Cities in MD

Beltsville Grade A
Score: 88.9/100
Germantown Grade A
Score: 88.9/100
Silver Spring Grade A
Score: 88.9/100
Frederick Grade A
Score: 88.9/100
Gaithersburg Grade A
Score: 88.9/100
Rockville Grade A
Score: 88.9/100

Similar Rankings Nationwide

#697 Glen Burnie, MD
Score: 80.1/100
#698 Ellicott City, MD
Score: 80.1/100
#699 Dundalk, MD
Score: 80.1/100
#700 Catonsville, MD
Score: 80.1/100
#701 Annapolis, MD
Score: 80.1/100
#702 Essex, MD
Score: 80.1/100

Severn Air Quality FAQs

Is Severn a good fit for people who care about long-term air quality?

Severn is a good option with a clean air score of 80.1 and a grade of B. Its PM2.5 annual mean of 6.6 µg/m³ reflects relatively low long-term particulate exposure.

How frequent is unhealthy air in Severn?

Severn reports 0% of days as unhealthy, consistent with its B grade and PM2.5 annual mean of 6.6 µg/m³. This indicates stable and clean air conditions throughout the year.

Is air quality in Severn improving or getting worse over time?

Air quality in Severn has shown an improving trend over recent years, showing a positive environmental shift for long-term residents.

Does air quality vary within Severn?

Air quality can vary within the city due to local traffic, industry, and location patterns, without naming specific districts.