Pennsylvania, United States. PM2.5 from 3 reference monitors, updated hourly.
6.1 µg/m³
Good
Latest hour (05:00 UTC), 0.4× the WHO 24-hour guideline.
Rank
24 h
–
not enough data
7 days
#2,046
of 2,330 · 4.1 µg/m³
30 days
#1,441
of 2,327 · 5.7 µg/m³
Year
#475
of 2,160 · 11.2 µg/m³
Why it ranks here
Seasonal. Over the past year its worst months were July, averaging up to 22.2 µg/m³ against 4.6 in its cleanest month. Seasonal peaks usually come from heating, crop burning, fire or dust seasons.
Based on Philadelphia's own measurements; causes are the usual kinds for a pattern like this, not a confirmed source.
Last 4 days, hour by hour
Times in UTC. Dashed line: WHO 24-hour guideline (15 µg/m³).
Every day for a year
Good 0–9.0Moderate 9.1+Unhealthy for sensitive groups 35.5+Unhealthy 55.5+Very unhealthy 125.5+Hazardous 225.5+No data
51 of 356 measured days were over the WHO 24-hour guideline.
Daily world rank
Rank on each day's board (1 = most polluted city that day).
2026 against 2025, month by month
Faded bars: 2025. A month shows once it has 10 measured days.
This week against past years
Mean PM2.5 for 24 Sept to 30 Sept in each year. Dashed line: WHO 24-hour guideline.
Monitors
Station
Operator
Type
MONUS Public Domain
AirNow
Reference
FABUS Public Domain
AirNow
Reference
RITUS Public Domain
AirNow
Reference
Passyunk SquareCC BY 4.0
AirGradient
Low-cost
PhiladelphiaCC BY 4.0
Ryan S.
Low-cost
2511 W Girard AveCC0 1.0
Clarity
Low-cost
3001 S 84th StCC0 1.0
Clarity
Low-cost
223 E Girard AveCC0 1.0
Clarity
Low-cost
7331 Lindbergh BlvdCC0 1.0
Clarity
Low-cost
511 W. Lehigh Ave.CC0 1.0
Clarity
Low-cost
AMS RITCC0 1.0
Clarity
Low-cost
3312 Walnut StCC0 1.0
Clarity
Low-cost
2922 S Broad StCC0 1.0
Clarity
Low-cost
1501 Point Breeze AveCC0 1.0
Clarity
Low-cost
1620 N 52nd StCC0 1.0
Clarity
Low-cost
2736 N Broad StCC0 1.0
Clarity
Low-cost
4110 Market StCC0 1.0
Clarity
Low-cost
51 N 57th StCC0 1.0
Clarity
Low-cost
N 9th StCC0 1.0
Clarity
Low-cost
1901 Walnut StCC0 1.0
Clarity
Low-cost
807 Lombard StCC0 1.0
Clarity
Low-cost
N 2225 N 33rd StCC0 1.0
Clarity
Low-cost
315 N 18th StCC0 1.0
Clarity
Low-cost
Cobbs Creek Pkwy & Greenway StCC0 1.0
Clarity
Low-cost
1739 E Passyunk AveCC0 1.0
Clarity
Low-cost
AMS SWA SiteCC0 1.0
Clarity
Low-cost
1900 W Susquehanna AveCC0 1.0
Clarity
Low-cost
60 W Chelten AveCC0 1.0
Clarity
Low-cost
2100 Pine StCC0 1.0
Clarity
Low-cost
5404 Baltimore AveCC0 1.0
Clarity
Low-cost
3200 Henry AveCC0 1.0
Clarity
Low-cost
5029 Ridge aveCC0 1.0
Clarity
Low-cost
3934 N 5th St.CC0 1.0
Clarity
Low-cost
2223 Richmond StCC0 1.0
Clarity
Low-cost
N 34th St & Mantua AveCC0 1.0
Clarity
Low-cost
2600 Penrose AveCC0 1.0
Clarity
Low-cost
South PhillyCC BY 4.0
AirGradient
Low-cost
6298 Eastwick AveCC0 1.0
Clarity
Low-cost
C028 (5501 North Broad Street)CC0 1.0
Clarity
Low-cost
6906 City AveCC0 1.0
Clarity
Low-cost
C029 (5400 Lincoln Hwy)CC0 1.0
Clarity
Low-cost
1401 John F Kennedy BlvdCC0 1.0
Clarity
Low-cost
Stinger Square ParkCC0 1.0
Clarity
Low-cost
1358 Ridge Ave, Philadelphia, PA 19123 CC0 1.0
Clarity
Low-cost
851 Cecil B Moore Ave (2)CC0 1.0
Clarity
Low-cost
Growing Together GardenCC0 1.0
Clarity
Low-cost
Lovie Love You - AQ HostCC0 1.0
Clarity
Low-cost
Philly Thrive - AQ HostCC0 1.0
Clarity
Low-cost
Foster Family - AQ HostCC0 1.0
Clarity
Low-cost
PAWS - AQ HostCC0 1.0
Clarity
Low-cost
WIS (AMS-LAB Site)CC0 1.0
Clarity
Low-cost
The city's value is the median of its reference monitors each hour; low-cost sensors are listed but not counted when reference monitors exist. Data via OpenAQ; licences as listed. How we rank. Embed this on your site.