Air Quality in Washington, District of Columbia
Real-time air quality index (AQI) and pollution levels for Washington. Updated hourly from OpenWeather.
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About Washington Air Quality
Washington, District of Columbia is home to approximately 712,816 residents. Air quality data for Washington comes from OpenWeather's global atmospheric monitoring, which combines satellite observations and atmospheric models to track pollutants including PM2.5, PM10, ozone (O₃), nitrogen dioxide (NO₂), carbon monoxide (CO), and sulfur dioxide (SO₂).
The Air Quality Index (AQI) is calculated based on the pollutant with the highest concentration relative to EPA standards. An AQI value of 0-50 represents good air quality, 51-100 is moderate, and values above 100 indicate unhealthy conditions for sensitive groups or the general population.
View the current AQI for Washington above to make informed decisions about outdoor activities, exercise, and health precautions. Our data is updated hourly to provide the most current information.
Understanding Air Quality in Washington
Common Pollutants in Washington
Air quality in Washington is primarily affected by six key pollutants tracked by environmental monitoring systems. PM2.5 (fine particulate matter) consists of tiny particles less than 2.5 micrometers in diameter that can penetrate deep into lungs and even enter the bloodstream. PM10 (coarse particles) includes dust, pollen, and mold spores that can irritate airways.
Ground-level ozone (O₃) forms when pollutants from vehicles and industry react with sunlight, often peaking during warm, sunny days. Nitrogen dioxide (NO₂) mainly comes from vehicle emissions and power plants. Carbon monoxide (CO) results from incomplete fuel combustion, while sulfur dioxide (SO₂) primarily originates from industrial facilities and power generation.
Factors Affecting Washington's Air Quality
Several factors influence air quality in Washington throughout the year. Weather patterns play a crucial role—temperature inversions can trap pollutants close to the ground, while wind helps disperse them. Humidity levels affect how certain pollutants form and behave in the atmosphere.
Traffic patterns significantly impact local air quality, with rush hours typically showing elevated pollutant levels. The city's geography, including proximity to industrial areas, major highways, and natural features, creates unique air quality patterns. Seasonal variations are also important—summer heat can increase ozone formation, while winter heating may raise particle pollution levels.
When to Check Air Quality in Washington
Residents of Washington should check air quality before planning outdoor activities, especially if you have respiratory conditions, are pregnant, or have young children. Morning checks are ideal for planning your day's activities. It's particularly important to monitor AQI during wildfire season, high-traffic events, temperature inversions, or when you notice hazy conditions. Athletes and outdoor workers should check conditions before extended outdoor exposure.
Protecting Your Health in Washington
On Good Air Quality Days
- • Enjoy outdoor activities and exercise without restrictions
- • Keep windows open for natural ventilation when comfortable
- • Plan outdoor events and gatherings
- • Great time for children's outdoor play
When Air Quality is Poor
- • Limit time spent outdoors, especially during peak pollution hours
- • Move exercise indoors or reschedule for when AQI improves
- • Keep windows and doors closed to prevent outdoor air from entering
- • Use air purifiers with HEPA filters indoors if available
- • Sensitive groups should wear N95 masks if outdoor exposure is necessary
Certain groups in Washington are more vulnerable to air pollution: children (their lungs are still developing), older adults (65+), people with asthma, COPD, or heart disease, pregnant women, and outdoor workers. If you're in one of these groups, pay close attention to daily AQI readings and adjust activities accordingly.
Health Recommendations for Washington
Good (0-50)
Air quality is satisfactory. Enjoy outdoor activities as usual.
Moderate (51-100)
Acceptable for most people. Unusually sensitive individuals should watch for symptoms.
Unhealthy for Sensitive Groups (101-150)
People with lung disease, children, and older adults should reduce prolonged outdoor exertion.
Unhealthy (151-200)
Everyone should reduce prolonged outdoor exertion. Sensitive groups should avoid it.
Quick Facts
- Population
- 712,816
- State
- District of Columbia
- ZIP Code
- 20001
- Timezone
- EDT
More District of Columbia Air Quality
State Overview
Frequently Asked Questions
What is a good AQI for Washington?
An AQI value between 0-50 (Green) is considered "Good" for Washington. This means air quality is satisfactory and air pollution poses little or no risk for residents.
How often is Washington air quality updated?
Air quality data for Washington is updated hourly from OpenWeather's global atmospheric monitoring system. We cache results for 1 hour to ensure fast response times while maintaining data freshness.
What pollutants are monitored in Washington?
OpenWeather tracks six major pollutants for Washington: Fine Particulate Matter (PM2.5), Coarse Particulate Matter (PM10), Ground-level Ozone (O₃), Nitrogen Dioxide (NO₂), Carbon Monoxide (CO), and Sulfur Dioxide (SO₂). Data is collected from satellite observations combined with atmospheric modeling.
Is it safe to exercise outdoors in Washington today?
Check the current AQI for Washington above. If the AQI is 0-100 (Green or Yellow), outdoor exercise is generally safe for most people. If AQI is above 100 (Orange or higher), sensitive individuals should reduce outdoor exertion. Our site provides specific health recommendations based on current conditions.