Philadelphia Real-Time AQI Tracker
Get Alerts For Unhealthy AQI In Your Area
When air quality in your area reaches unhealthy levels, we'll send you a quick alert, along with expert tips on how to reduce your exposure.
What's Actually In Philadelphia Air Today?
What High AQI Means for Your Lungs in Philadelphia
How to Read AQI
The Air Quality Index (AQI) measures how polluted the air is and how it may affect your health.
0–50 (Good): Air quality is satisfactory.
51–100 (Moderate): Acceptable, but some pollutants may pose minor concerns.
101–150 (Unhealthy for Sensitive Groups)
151–200 (Unhealthy)
201–300 (Very Unhealthy)
301+ (Hazardous)
Moderate
Still okay for most, but if you have asthma or allergies, take it easy and avoid long outdoor workouts.
Shop MERV 11 filters→What's the Right Filter for Your AQI Level?
Philadelphia Air Quality Index (AQI) Today
What Is The Air Quality In Philadelphia Today?
Check the live air quality map above for current conditions in Philadelphia. It reads from EPA AirNow monitors across the Delaware Valley and refreshes hourly, showing the latest AQI for your part of the city and the pollutant behind it. From 0 to 50 is good and 51 to 100 is moderate, while 101 or higher means scaling back outdoors and filtering indoors. That is the current air quality in Philadelphia, in real time.
TL;DR
Philadelphia’s AQI varies block by block, so check the live air quality map above for the reading nearest you. Two pollutants drive it: ground-level ozone, worst on hot afternoons from late April through September, and PM2.5, which runs year-round and spikes with wildfire smoke. Past 100, close the house, put an EPA-recommended MERV 13 in the HVAC if you have one, and run a HEPA air cleaner in each occupied room.
Key Takeaways
The Philadelphia AQI changes block to block. PM2.5 along the I-95 corridor reads higher than blocks three miles inland. Use the nearest station.
Past AQI 100, run both layers. An EPA-recommended MERV 13 in the HVAC if you have one, plus a HEPA air cleaner in each occupied room.
Breathe Philly put a monitor within 1.5 miles of every Philadelphian in February 2026.
Filtration solves half the problem. MERV filters capture particles, not gases, so they do nothing for ozone. Filterbuy says so even though it costs sales.
How Do You Read The Philadelphia AQI Map And Its Categories?
Every dot on the Philadelphia AQI map above is one station’s latest reading, so zoom this air quality map of Philadelphia in on your ZIP code. The six categories run Good, Moderate, Unhealthy for Sensitive Groups, Unhealthy, Very Unhealthy, and Hazardous, from 0 to 500 on the EPA’s scale. They mean the same thing in every city. What changes is the local advice.
Source: EPA AirNow AQI Basics.
What The Philadelphia AQI Does Not Tell You
The index is useful and incomplete. It measures outdoor air, so a gas range or a candle can push indoor PM2.5 past whatever the map shows, and pollen is not among the six pollutants it covers.
It also reports only the worst pollutant, not the mix. An AQI of 80 driven by ozone and an 80 driven by PM2.5 call for opposite responses: the first is a gas your filter cannot touch, the second is what a MERV 13 captures. The live map names the dominant pollutant, and that label often matters more than the number.
Why Is Philadelphia’s Air Pollution So Bad?
Two pollutants do most of the damage in Philadelphia, and they arrive in different seasons.
Ground-level ozone forms when sunlight cooks the emissions off I-95, I-76, and the industrial Northeast Corridor. Philadelphia ozone levels climb into Code Orange on hot afternoons from late April through September, worst between 2 and 8 PM, exactly when school lets out and rec leagues take the field. Pennsylvania DEP posts Action Day declarations, and the National Weather Service in Mount Holly publishes its air quality outlook ahead of local news.
PM2.5 in Philadelphia, or fine particulate matter, comes from vehicle exhaust, the Marcus Hook industrial complex, winter wood smoke, and Canadian wildfire smoke. For current PM2.5 levels, refer to the live air quality map above.
The Philadelphia region fails all three air quality measures the American Lung Association grades, where most metros that fail one pass another.
What Is Breathe Philly?
Breathe Philly is the City of Philadelphia’s real-time air quality sensor network, launched February 18, 2026 by the Department of Public Health. Its 76 sensors put every Philadelphian within 1.5 miles of a monitor, measuring PM2.5 and nitrogen dioxide (NO₂) hourly and feeding a dashboard with email alerts. Before it, ten stations covered 142 square miles, leaving neighborhoods out of range.
Use the reference number for the official Philadelphia AQI, and Breathe Philly to see if your block runs hot. Check the Breathe Philly dashboard or the city’s air quality data.
Is The Air Quality Bad In Philadelphia Today?
Whether Philadelphia air pollution today counts as bad depends on who is asking. Pull your AQI from the map above, then find your row.
Those thresholds follow EPA’s AQI guidance. Children breathe more air per kilogram of body weight than adults, so the same afternoon delivers a larger dose (American Lung Association). If you have asthma, COPD, or a heart condition, follow your clinician’s plan and the guidance at AirNow.
What Should You Do Indoors When Philadelphia’s AQI Climbs?
Check AirNow and any Philadelphia Department of Public Health guidance first. Then work through four steps, which Filterbuy recommends starting at AQI 100.
Close the house up. Windows, doors, and outdoor air intakes shut. Do not add indoor pollution while smoke is in: no candles, no frying, no vacuuming without a sealed unit.
Set the thermostat fan to On. Auto only filters while the system is heating or cooling; On filters continuously, which is what the EPA advises during smoke events.
Put MERV 13 in the HVAC, if you have one. EPA recommends MERV 13 or higher in the central system during smoke events, and says most furnaces accommodate one as long as it is replaced often. MERV 8 and MERV 11 sit lower on the ladder; smoke is MERV 13, in your size. Our MERV comparison covers the differences.
Run a portable HEPA air cleaner in each occupied room, bedrooms first. That is a Filterbuy recommendation going further than EPA’s single clean room. Size each by EPA’s rule: a smoke CADR of at least two-thirds the room’s square footage, so a 300 square foot bedroom wants roughly 200.
Much of Philadelphia’s row home stock has no ductwork, so there is no whole-home layer. In those homes portable HEPA cleaners are the primary defense, not a supplement.
Where This Recommendation Comes From
Filterbuy has built air filters in the United States since 2013, from plants in Alabama, Florida, Utah, and Pennsylvania. That last one is why Mid-Atlantic air is not an abstraction for us. We recommend a tier and a size, never one product as the smoke filter.
One position costs us sales. A filter does nothing for ozone, because MERV ratings measure particle capture while ozone and NO₂ are gases that pass straight through a pleat. Filtration reduces what is in the air. It does not make indoor air safe, and never replaces official guidance.
“The mistake I see most often in Philadelphia homes is timing, not filter choice. People wait until they smell smoke, and by then PM2.5 has settled into carpets and the HVAC coil. Switch to MERV 13 in early May, before ozone season.”
— David Clark, Licensed HVAC Technician, Filterbuy HVAC Solutions
How Does Wildfire Smoke Affect Philadelphia’s Air Quality?
Wildfire smoke is a MERV 13 problem, and Philadelphia’s worst air on record came from it. On June 7–8, 2023, smoke from Quebec fires pushed the city past AQI 350 and into Code Maroon, the worst reading since at least 2008 according to EPA data. Canadian smoke rides the patterns that bring cold fronts down the East Coast, then settles under an inversion.
All four steps above apply, plus one. Check your dryer vent and bathroom exhaust fans, whose backdraft dampers turn into entry points if they do not seal tightly. The Filterbuy Philadelphia wildfire smoke map tracks fire perimeters, and our best MERV filter for wildfire smoke guide covers the rest.
Supporting Statistics
1. Philadelphia County averages 5.3 unhealthy particle-pollution days and 6.2 high-ozone days per year. Both earn F grades, and year-round particle pollution worsened from 26th worst in the nation to 17th.
Source: American Lung Association, State of the Air 2026
2. Americans spend about 90% of their time indoors, where some pollutants run 2 to 5 times higher than outdoor levels. The people most susceptible to air pollution spend even more time inside.
Source: U.S. EPA, Report on the Environment
3. Asthma emergency department visits ran 17% above expected nationally during the 2023 Canadian wildfire smoke days. The region covering Pennsylvania recorded five smoke days, more than any other, peaking at a 24-hour PM2.5 average of 259 µg/m³.
Source: CDC, MMWR, August 25, 2023
Frequently Asked Questions
At what AQI do Philadelphia schools cancel outdoor practice?
Code Orange, AQI 101 to 150, is where most districts move practice indoors, and Code Red cancels it. Check the forecast the night before, since ozone peaks from 2 to 8 PM.
I have window AC units, not central air. What do I do?
Set the unit to recirculate, seal the frame gaps, and run a HEPA cleaner in each occupied room. A window unit’s screen is a lint filter, not a particle filter.
How often should I change my air filter in Philadelphia?
Every 90 days is the normal interval. During a smoke event, skip the schedule and inspect it: replace the filter when it looks dark, well before the manufacturer’s interval if needed. Keep spares on hand.
Can I open the windows at night when the AQI is high?
It depends on the pollutant, which the live map names. Ozone falls off after sunset, so a hot summer evening is often the cleanest time to air out a row home. Winter reverses that, since cold, calm nights trap wood smoke near the ground.
Check Your Air, Then Fix What You Control
“Most air quality pages hand you a number and stop. What people here ask me is what to do when the reading is bad and the house has no central air.”
— Michelle Wan, Brand Manager and Air Quality Writer, Filterbuy
The Philadelphia air quality map tells you what is coming in. Your Filterbuy filter decides how much stays. Find your filter size or see which MERV rating fits your home.
More: Pennsylvania AQI · Pittsburgh · Allentown · U.S. AQI map
Glossary
AQI (Air Quality Index): The EPA’s 0-to-500 scale for outdoor air pollution, in six categories from Good to Hazardous.
PM2.5: Fine particulate matter 2.5 micrometers or smaller, about 30 times thinner than a human hair.
Ground-level ozone (O₃): A gas formed when sunlight reacts with vehicle and industrial emissions.
MERV: Minimum Efficiency Reporting Value, the 1-to-16 scale for how well a filter captures particles.
Breathe Philly: The City of Philadelphia’s network of 76 neighborhood air quality sensors, live since February 2026.