Pasadena, CA
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.
Pasadena, CA air quality summary: Pasadena, CA, has a clean air score of 39.6 and a grade of F. The city's PM2.5 annual mean of 13 is considered elevated for long-term exposure. Pasadena records a PM2.5 annual mean of 13, indicating elevated long-term exposure for its residents. Long-term air quality in Pasadena has been worsening over recent years.
Clean Air Score
A score of 39.6 and a grade of F indicate significant and persistent air quality challenges. These ratings reflect particulate concentrations that frequently exceed long-term environmental health guidelines.
🏡 What This Means for Buying
Prospective residents should carefully weigh the city's elevated particulate levels as a major factor in their long-term housing decisions. Evaluation of regional environmental conditions is a critical part of the due diligence process for the area.
Indoor Air Quality in Pasadena, CA
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 Pasadena.
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 Pasadena:
- Wildfire smoke infiltration (PM2.5)
- 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 Pasadena Homes:
🩺 My Health Risk Assessment
See how Pasadena's air quality affects you and your family specifically.
Health Advice
Reduce prolonged outdoor exertion.
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</> Create Free Widget🏡 Property Value Impact Analysis
Between 2019 and 2024, Pasadena's air quality worsened by 2.3 μg/m³. Based on NBER studies, this change correlates with a estimated 9.2% decrease in relative property value retention.
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Why Pasadena earned a 39.6
Raw inputs, scoring weights, and data coverage for this city.
Best Time to Run
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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% | 0 |
| Unhealthy Days | 25% | 67.2 |
| 5-Year Trend | 20% | 38.5 |
| Seasonal Variability | 10% | 80.8 |
| Extreme Events | 5% | 95 |
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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Pasadena Air Quality FAQs
Is Pasadena a good fit for people who care about long-term air quality?
Pasadena faces significant challenges with a score of 39.6 and a grade of F. The annual PM2.5 mean of 13 reflects elevated chronic exposure levels.
How often does Pasadena experience unhealthy air days?
Pasadena experiences unhealthy air days 1.6% of the time. This frequency contributes to its grade of F and reflects a higher exposure risk compared to many other regions.
Is air quality in Pasadena improving or getting worse over time?
Air quality in Pasadena has shown a worsening trend in recent years, requiring residents to monitor long-term environmental patterns.
Does air quality vary across different parts of Pasadena?
Air quality can fluctuate within Pasadena due to geographic features, local traffic density, and seasonal patterns. Residents may find that conditions differ significantly between various neighborhoods.