On June 7, 2023, Washington, DC's air quality index climbed to 412. The sky over K Street turned orange that morning, the sun dimmed at noon, and the smell of woodsmoke hung in a city a thousand miles from the nearest fire. Canadian wildfire smoke had settled over the District for almost a week. Our DC customers ordered three times their normal volume of MERV 13 filters that month — an honest reaction from people who realized that the air outside their windows had turned hazardous and the air inside their homes was about to follow.
That summer changed how a lot of DC residents think about checking the air. The live AQI map above does the heavy lifting now. Today's reading reflects whatever is drifting across Foggy Bottom, settling along the Anacostia waterfront, or climbing along the Beltway corridor at this exact moment. If you've got kids playing outside this weekend or anyone in the house who reacts to pollen and smoke, the number on that map is the first thing worth knowing.
The live AQI map for Washington, DC, shows real-time air quality readings sourced from EPA AirNow monitoring stations across the District. Today's reading reflects the highest concentration of a single criteria pollutant — most often ozone in summer or PM2.5 during wildfire smoke events — at the station nearest your neighborhood.
Here's what each AQI band means for your household.
0 to 50 (Green, Good). Open the windows. Outdoor air is satisfactory.
51 to 100 (Yellow, Moderate). Acceptable for most. Sensitive family members may want to limit prolonged outdoor exertion.
101 to 150 (Orange, Unhealthy for Sensitive Groups). Children, older adults, and anyone with asthma should reduce outdoor activity.
151 to 200 (Red, Unhealthy). Everyone limits outdoor exposure. Keep windows closed and make sure your HVAC filter is fresh.
201 to 300 (Purple, Very Unhealthy). Stay indoors and run the HVAC on recirculate. Health emergency conditions for sensitive groups.
301+ (Maroon, Hazardous). Serious effects for everyone. Indoor air quality control becomes critical.
Pro tip: when DC's outdoor AQI hits orange or higher, your HVAC filter is doing the heavy lifting. A clean MERV 13 filter captures about 90 percent of wildfire smoke particles and 85 percent or more of the fine particulates that drive elevated AQI readings, well before they reach your family's lungs.
DC's AQI shifts by neighborhood and by pollutant. The live map is your first read, not your last.
Summer ozone and Canadian wildfire smoke are the two highest-impact AQI events DC households should plan for.
Indoor air can run two to five times worse than outdoor air, so the number outside is only half the picture.
MERV 13 is the residential filter the EPA points to for wildfire smoke and elevated AQI episodes.
Filter replacement every 60 to 90 days protects performance during DC's high-pollen and high-smoke months.
Washington sits in a tough spot for air quality. The District absorbs vehicle exhaust from one of the densest commuter regions in the country, summer humidity that traps fine particles close to the ground, federal-fleet diesel idling outside government buildings, and a tree canopy that releases some of the heaviest spring pollen loads on the East Coast.
Four pollutants drive most of the District's AQI variability.
Ground-level ozone. Summer heat and sun cook nitrogen oxides from vehicles and stationary sources into ozone. DC has been in nonattainment of the federal ozone standard for years, which is why code orange and code red ozone action days are now a regular feature of June through August.
Fine particulate matter (PM2.5). Regional power plants, transportation exhaust, and construction sites add a steady baseline of PM2.5 across the city, and winter inversion days trap it close to the ground for hours at a time.
Tree pollen. Oak and birch make DC one of the most pollen-heavy capitals in the country during late March through May, and allergy-driven AQI proxies often spike independently of ozone or particles.
Wildfire smoke from Canada. The June 2023 smoke event wasn't an outlier. Smoke from Canadian wildfires now reaches the Mid-Atlantic most summers, and forecasters track multi-day plumes routinely.
The Air Quality Index (AQI) translates concentrations of six federal-criteria pollutants into a single 0-to-500 scale. The number you see on the live map for the District is the highest single pollutant reading at the nearest monitoring station, which is why a yellow ozone day can still mean green PM2.5 (or vice versa).
Here's what each AQI band means for your family.
0 to 50 (Green, Good). Outdoor air is satisfactory. Open windows, run errands, let kids play outside without worry.
51 to 100 (Yellow, Moderate). Acceptable for most. People who are unusually sensitive to ozone or particles, including some children and older adults, may want to limit prolonged outdoor exertion.
101 to 150 (Orange, Unhealthy for Sensitive Groups). Anyone with asthma, COPD, heart disease, or pollen sensitivity should reduce outdoor activity. Across DC, this is the band where Beltway commuters and outdoor school activities deserve a second look.
151 to 200 (Red, Unhealthy). Everyone limits outdoor exposure. Keep windows closed and make sure your HVAC filter is fresh.
201 to 300 (Purple, Very Unhealthy). Health emergency conditions for sensitive groups. Stay indoors and run the HVAC on recirculate.
301+ (Maroon, Hazardous). Serious health effects for everyone. Indoor air quality control becomes critical.
The biggest misconception we hear from DC homeowners is that an elevated outdoor AQI is purely an outdoor problem. It isn't. Outdoor pollution travels indoors through window and door leakage, HVAC outside-air intake, and particulates tracked in on shoes, clothing, and pets. By the time a smoke event or ozone spike settles in, the air inside your home often carries the same pollutants at meaningful concentrations.
Older DC row homes and brick walk-ups, especially the ones built before modern envelope sealing standards, are particularly vulnerable. Drafts that feel charming in cold weather become liabilities when the AQI climbs past 100.
This is why HVAC filtration is your household's first line of defense. The EPA points to MERV 13 as the residential filter rating that meaningfully reduces wildfire smoke particles and elevated PM2.5 indoors. For a national overview of how each region is tracking, you can view the full live air quality index map for North America and see how DC compares to other major markets.
DC residents call us during every summer wildfire smoke event with the same question: is my current filter going to be enough? After manufacturing filters for over a decade and serving more than two million households, my answer is the same one I'd give my own family. If you live anywhere in the District and the AQI is approaching the orange band, you should already be running a MERV 13. The cost difference per month is pennies. The protection for your kids, your parents, and anyone in the home with respiratory sensitivity is everything. Treat it like sunscreen, not like an optional upgrade.
— Filterbuy Team
Knowing the right resources makes the difference between reacting to bad air and getting ahead of it. The seven sources below are the ones we recommend to DC customers who want to track air quality the way local environmental scientists do.
AirNow is the federal AQI data source that every other map and app pulls from. Type "Washington, DC" into the site, and you'll see the live reading from the closest monitoring station along with which pollutant is driving the number and a plain-language health note for the day. This is the source of truth when other apps disagree.
Source: EPA AirNow AQI Basics
The Department of Energy and Environment publishes the District's Healthy Air Actions guidance. It covers what residents should do during ozone action days, how transportation choices affect your neighborhood's air, and which protective steps to take indoors. It's written by the people who actually monitor DC's air every day.
Source: DOEE Healthy Air Actions
The Metropolitan Washington Council of Governments runs the regional air quality forecast for DC, Maryland, and Virginia. It's the same forecast local news stations use when they announce a code orange day, with the added value of multi-day projections so you can plan exercise and outdoor activities ahead of time.
Source: MWCOG Air Quality Forecast
The American Lung Association's annual State of the Air report grades every US metro on ozone and on short- and year-round particle pollution. The Washington-Baltimore-Arlington metro consistently ranks near the bottom for ozone, and recent reports dropped DC's particle pollution grade to an F after the 2023 wildfire smoke events.
Source: American Lung Association State of the Air
The CDC's Asthma and Community Health Branch tracks how outdoor pollutants like ozone and PM2.5 worsen asthma symptoms and trigger attacks. Their guidance also explains the indoor-outdoor connection, which matters when DC's outdoor AQI climbs and your home's air becomes the next line of defense for someone managing asthma.
Source: CDC Asthma and Community Health
The National Park Service operates an air quality monitor near the National Mall on Hains Point and tracks pollutants like ozone, nitrogen, and sulfur deposition, and visibility across DC-area parks. NPS data feeds into the broader regional air quality picture and gives you a different vantage point than the agency-run street-level monitoring stations.
Source: NPS National Capital Region Air and Climate
NOAA's HRRR-Smoke model forecasts where wildfire smoke is moving across North America in 36-hour increments. When Canadian fires are active in summer, this is the tool that tells you a day in advance whether a plume will reach the Mid-Atlantic and how dense it'll be when it gets here.
Source: NOAA HRRR-Smoke Forecast
These are the three numbers that change how most homeowners think about indoor air quality once they see them in context.
EPA research shows that indoor levels of some pollutants run two to five times higher than outdoor concentrations, and occasionally more than 100 times higher during peak activities. For DC residents who spend most of the day indoors, the AQI reading outside is only half the picture. The other half is what's recirculating through your HVAC system right now.
Source: US EPA Indoor Air Quality
The Asthma and Allergy Foundation of America reports that nearly 28 million people in the United States have asthma, or roughly 1 in 12. In a city with chronic ozone nonattainment and recurring summer smoke events, every elevated AQI day is a day when those neighbors are more likely to reach for an inhaler, miss work, or end up in an emergency department.
Source: AAFA Asthma Facts
A 2025 Harvard T.H. Chan School of Public Health study linked exposure to wildfire-specific PM2.5 with increased emergency department visits for depression, anxiety, and other mood disorders for up to seven days after the smoke event. For a region now seeing regular summer Canadian smoke episodes, the health stakes go well beyond breathing.
Source: Harvard T.H. Chan School of Public Health Study
The hard truth about DC air quality is that it's no longer a problem you can outrun by waiting for fall. Summer ozone, spring pollen, winter PM2.5 inversions, and the new annual reality of Canadian wildfire smoke mean that some part of every year is going to push your household's air into a range that affects sensitive family members. Checking a live AQI map handles the awareness side. The harder part is running a high-MERV filter, sealing the leaks you can find, and replacing filters every 60 to 90 days during smoke and pollen months. Air quality in the District is going to remain unpredictable for the foreseeable future, but with the right setup at home, your indoor air can stay steady anyway.
Bookmark this page and check the live AQI map before you open windows or send kids outside on hazy, hot, or smoky days.
Sign up for air quality alerts from Clean Air Partners or AirNow so code orange and code red days reach you before you walk out the door.
Use the Filterbuy filter sizing tool to find the right MERV 13 filter for your specific HVAC system.
Set a 60-to-90-day filter replacement reminder on your phone or smart home assistant, with extra changes during heavy pollen or smoke months.
Share this page with one neighbor who has young kids, an elderly parent, or anyone living with asthma or COPD.
DC's air quality shifts hour by hour and neighborhood by neighborhood. The fastest way to check is the live AQI map at the top of this page, which pulls real-time data from EPA monitoring stations across the District. Anything in the green or yellow band is safe for most people. Orange and above means sensitive groups should limit outdoor exposure, and red or higher means everyone limits outdoor activity and keeps windows closed.
A healthy AQI for DC is any reading in the 0-to-50 (Green) range. The 51-to-100 (Yellow) range is acceptable for most healthy adults, but children, older adults, and anyone with asthma or heart disease should pay attention. Anything 101 or higher pushes the District into territory where indoor air protection matters more, especially for sensitive household members.
Washington's ozone comes from heat, sun, and emissions from vehicles, federal fleet diesel, and regional power generation. Hot, sunny, low-wind summer days create the conditions for ground-level ozone formation. The District has been in nonattainment of the federal ozone standard for years, which is why code orange and code red ozone days are routine from June through August.
Smoke from large Canadian wildfires can travel thousands of miles on prevailing wind patterns and settle over the Mid-Atlantic for multiple days. When that happens, DC's PM2.5 readings can climb from green to red or purple in under 24 hours. The June 2023 smoke event pushed local AQI past 400, which is hazardous for everyone. NOAA's HRRR-Smoke model is the best forecasting tool to watch for an incoming plume.
For most DC households, MERV 13 is the right baseline. It captures fine particles from wildfire smoke, traffic exhaust, and pollen far better than the standard MERV 8 fiberglass filters most HVAC systems ship with. If your system can handle the static pressure increase, MERV 13 gives you the best balance of protection and airflow. Households with severe asthma may want to add a portable HEPA unit during high-AQI events.
During DC's high-pollen and high-smoke months, change your filter every 60 days. The rest of the year, every 90 days is fine. Pets, children with allergies, or a home near a heavy traffic corridor like the Beltway shorten that interval further. A clogged filter doesn't just stop protecting you; it also stresses your HVAC system and raises your energy bill.
DC's real-time AQI data comes from six DOEE-operated monitoring stations across the District, plus partner sites run by NPS and the regional MWCOG network. Those readings feed into EPA's AirNow database, and every major air quality map and app then republishes them. The data you see on this page traces back to those federal and District monitoring stations.
Watching the outdoor AQI is the easy part. Protecting the air your family actually breathes inside your home takes one decision and one purchase. A fresh, properly sized MERV 13 filter is the single highest-impact change most DC households can make right now, before the next ozone action day, smoke plume, or pollen surge.
