Data: EPA AirNow, FEMA National Risk Index Last verified: 2026-07-18

What is AQI?

The Air Quality Index (AQI) is a standardized scale from 0 to 500 that measures air pollution levels. 0-50 is "Good," 51-100 is "Moderate," 101-150 is "Unhealthy for Sensitive Groups," and above 150 is "Unhealthy" for everyone. AQI tracks five major pollutants: ground-level ozone, particulate matter (PM2.5 and PM10), carbon monoxide, sulfur dioxide, and nitrogen dioxide. Washington's average AQI of 68 falls in the "Moderate" range.

Air Quality Map: Washington, DC

Each dot represents a ZIP code. Color indicates AQI level. Tap a dot for details.

Good (0-50) Moderate (51-100) USG (101-150) Unhealthy (151+)

Air Quality by ZIP Code in Washington

AQI varies across Washington's 274 ZIP codes based on proximity to pollution sources and local geography.

ZIP Code	AQI	Category	Wildfire	Mold
20001	68	Moderate	10	49	View report →
20002	68	Moderate	10	64	View report →
20003	68	Moderate	10	50	View report →
20004	68	Moderate	10	38	View report →
20005	68	Moderate	10	52	View report →
20006	68	Moderate	10	55	View report →
20007	68	Moderate	10	67	View report →
20008	68	Moderate	10	58	View report →
20009	68	Moderate	10	61	View report →
20010	68	Moderate	10	61	View report →
20011	68	Moderate	10	64	View report →
20012	68	Moderate	10	61	View report →
20013	68	Moderate	10	53	View report →
20015	68	Moderate	10	64	View report →
20016	68	Moderate	10	61	View report →

Showing 15 of 20 ZIP codes. View all.

Air Quality Overview

Washington, District of Columbia has moderate air quality with an average AQI of 68. Air quality is acceptable, though some pollutants may be a concern for a small number of people who are unusually sensitive to air pollution. The dominant pollutant is Ozone.

The Air Quality Index (AQI) is an EPA-standardized scale from 0 to 500. Values below 50 are "Good," 51-100 "Moderate," 101-150 "Unhealthy for Sensitive Groups," 151-200 "Unhealthy," 201-300 "Very Unhealthy," and above 300 "Hazardous."

Dominant Pollutant: Ozone

Ground-level ozone forms when pollutants from cars, power plants, and industrial facilities react with sunlight. Unlike stratospheric ozone, ground-level ozone is harmful to breathe.

Health effects of ozone exposure:

• Irritation of the respiratory system
• Reduced lung function
• Aggravation of asthma and chronic lung diseases
• Increased susceptibility to respiratory infections

Peak times: Ozone levels are typically highest on hot, sunny afternoons. Exercise outdoors in the morning when levels are lower.

Air Quality by ZIP Code in Washington

AQI varies across Washington's 274 ZIP codes based on proximity to pollution sources, traffic patterns, and local geography:

Showing 15 of 274 ZIP codes. Check your specific ZIP for detailed data.

Wildfire Smoke Risk

Washington has a low wildfire smoke risk with an average smoke risk score of 10 (scale 0-100). However, smoke from distant wildfires can temporarily degrade air quality even in low-risk areas.

Metric	Value
Avg. smoke risk score	10
Max smoke risk score	16
Fires within 100 km	479
High-risk ZIP codes	0

Wildfire smoke contains PM2.5, carbon monoxide, and volatile organic compounds. Even short-term exposure can trigger asthma attacks and respiratory distress.

Indoor Mold Risk

Washington has an average mold risk score of 53 out of 100, with 17 ZIP codes in the high-risk category.

Factor	Value
Mold risk score	53/100
Average humidity	64% RH
High-risk ZIPs	17
Peak season	summer high

Mold risk is influenced by humidity levels, housing age (older homes have more moisture issues), flood history, and water infrastructure quality. Indoor humidity above 60% creates favorable conditions for mold growth.

Signs of mold problems: musty odors, visible growth on walls or ceilings, worsening allergies indoors, condensation on windows. Professional mold testing ($300-$600) can identify hidden issues.

Health Recommendations

With moderate air quality (AQI 68), most people can be active outdoors. Sensitive groups should take precautions:

• Sensitive groups (asthma, COPD, heart disease): consider reducing prolonged outdoor exertion
• Keep windows closed on high-pollution days
• Use a HEPA air purifier in main living areas
• Check AirNow.gov before outdoor exercise

Washington vs. Nearby District of Columbia Cities

How Washington's air quality compares to nearby cities:

ZIP Codes in Washington

Washington covers 274 ZIP codes. Air quality can vary by neighborhood based on proximity to highways, industrial areas, and green spaces. Check your specific ZIP code for localized data.

Data Sources

• Air quality: EPA AirNow - real-time and historical AQI data
• Wildfire risk: FEMA National Risk Index
• Mold risk: Derived from EPA, FEMA, Census ACS (humidity, housing age, flood history)
• Monthly AQI: EPA Air Quality Statistics

Updated daily.