| Allentown, United States (USA) | Good | Details |
| Alliance, United States (USA) | - | Details |
| Allumiere, Italy | Good | Details |
| Allumiere - v.Aldo Moro, Italy | Hazardous | Details |
| Al Mafraq, United Arab Emirates (UAE) | Unhealthy | Details |
| Al Maqtaa, United Arab Emirates (UAE) | Moderate | Details |
| Almaty, Kazakhstan | Good | Details |
| Almoloya de Juárez, Mexico | - | Details |
| Alnabru, Norway | Good | Details |
| Alpine, United States (USA) | Good | Details |
| Al Qua'a, United Arab Emirates (UAE) | Unhealthy | Details |
| ALSIP, United States (USA) | Good | Details |
| Al Tawia, United Arab Emirates (UAE) | Unhealthy | Details |
| Alto Hospicio, Chile | Moderate | Details |
| Alton, United States (USA) | - | Details |
| Altoona, United States (USA) | Good | Details |
| Alvim, Norway | Good | Details |
| Amanda Elem, United States (USA) | - | Details |
| Amanzimtoti, South Africa | - | Details |
| Amarillo Texas A&M C, United States (USA) | Good | Details |
| Amasya, Turkey | Good | Details |
| Amasya - Merzifon, Turkey | Good | Details |
| Amasya - Şehzade, Turkey | Moderate | Details |
| Amasya - Suluova, Turkey | Good | Details |
| Ametlla de Mar, l', Spain | Good | Details |
| Amherst, United States (USA) | - | Details |
| Amman, Jordan | Moderate | Details |
| Amposta, Spain | Very Unhealthy | Details |
| Amsterdam-Einsteinweg, Netherlands | Moderate | Details |
| Amsterdam-Hoogtij, Netherlands | Good | Details |
| Amsterdam-Jan van Galenstraat, Netherlands | Good | Details |
| Amsterdam-Kantershof (Zuid Oost), Netherlands | Good | Details |
| Amsterdam-Nieuwendammerdijk, Netherlands | Good | Details |
| Amsterdam-Oude Schans, Netherlands | Good | Details |
| Amsterdamplein, South Africa | - | Details |
| Amsterdam-Spaarnwoude, Netherlands | Good | Details |
| Amsterdam-Sportpark Ookmeer (Osdorp), Netherlands | Good | Details |
| Amsterdam-Stadhouderskade, Netherlands | Moderate | Details |
| Amsterdam-Van Diemenstraat, Netherlands | Moderate | Details |
| Amsterdam-Vondelpark, Netherlands | Good | Details |
| Amsterdam-Westerpark, Netherlands | Good | Details |
| Anacortes-202 Ave (S, United States (USA) | Good | Details |
| Anacortes-Bartholome, United States (USA) | Moderate | Details |
| Anaheim, United States (USA) | Good | Details |
| Anaheim Near Road, United States (USA) | Good | Details |
| Ancora State Hosptia, United States (USA) | - | Details |
| Andacollo, Chile | Moderate | Details |
| Anderson, United States (USA) | Good | Details |
| Anderson-Eastside El, United States (USA) | Good | Details |
| Andrew Johnson Elem., United States (USA) | - | Details |
| Ankara - Bahçelievler, Turkey | Good | Details |
| Ankara - Batıkent, Turkey | Good | Details |
| Ankara-Çankaya, Turkey | Good | Details |
| Ankara - Demetevler, Turkey | Good | Details |
| Ankara - Etimesgut, Turkey | Good | Details |
| Ankara - Etlik, Turkey | Good | Details |
| Ankara - Kayaş, Turkey | Good | Details |
| Ankara - Keçiören Sanatoryum, Turkey | Good | Details |
| Ankara - Mamak, Turkey | Good | Details |
| Ankara - Ostim, Turkey | Good | Details |
| Ankara - Polatlı, Turkey | Good | Details |
| Ankara - Sincan, Turkey | Moderate | Details |
| Ankara - Siteler, Turkey | Good | Details |
| Ankara - Sıhhıye, Turkey | Good | Details |
| Ankara Teknofest - 2023, Turkey | - | Details |
| Ankara - Törekent, Turkey | Good | Details |
| Ankara - Ulus, Turkey | Moderate | Details |
| Ankara Yaşamkent, Turkey | Good | Details |
| Ann Arbor, United States (USA) | - | Details |
| Antalya, Turkey | Moderate | Details |
| Antalya - Alanya, Turkey | Good | Details |
| Antalya - Gazipaşa, Turkey | Moderate | Details |
| Antalya - Kumluca, Turkey | Moderate | Details |
| Antalya - Manavgat, Turkey | Good | Details |
| Antalya - Muratpaşa, Turkey | Good | Details |
| Antalya - Serik, Turkey | Good | Details |
| Antalya - Trafik, Turkey | Unhealthy | Details |
| Antananarivo, Morocco | Moderate | Details |
| Anthony, United States (USA) | Good | Details |
| Antofagasta, Chile | Moderate | Details |
| Anzac, Canada | Moderate | Details |
| Anzac Square, New Zealand | - | Details |
| Apache Junction, United States (USA) | Good | Details |
| Apodaca, Mexico | Moderate | Details |
| APOLLO BEACH, United States (USA) | Good | Details |
| APPLETON AAL, United States (USA) | Good | Details |
| Apple Valley, United States (USA) | Good | Details |
| Aprilia 2, Italy | Good | Details |
| Arboretum - RBCAA, South Africa | - | Details |
| Arboretum – Water Facility, South Africa | - | Details |
| Archbold Biomedical, United States (USA) | - | Details |
| Ardahan, Turkey | Good | Details |
| Arden Arcade - Del P, United States (USA) | Good | Details |
| Ardrossan, Canada | Moderate | Details |
| Arendtsville, United States (USA) | - | Details |
| Arendtsville, United States (USA) | Good | Details |
| Arenula, Italy | Good | Details |
| Arica, Chile | Moderate | Details |
| Arima, Trinidad and Tobago | - | Details |
| Arlington Municipal, United States (USA) | - | Details |
