Air Quality in Puerto Rico

Puerto Rico has 12 counties with EPA air quality monitoring. Air quality is generally improving across the state, with an average of 174 "Good" days per county per year. The best air quality is in Caguas (median AQI 3) and the most polluted is Catano (median AQI 51).

County	Median AQI	Max AQI	Good Days	Unhealthy Days	Trend	Top Pollutant
Adjuntas	14	23	7	0	↓ improving	PM2.5
Bayamon	27	124	268	1	↓ improving	PM2.5
Caguas	3	174	343	1	↓ improving	PM2.5
Catano	51	162	168	41	↑ worsening	PM2.5
Fajardo	28	84	88	0	→ stable	PM2.5
Guayama	15	53	51	0	↓ improving	PM10
Guayanilla	32	80	36	0	↓ improving	PM2.5
Guaynabo	31	81	91	0	↑ worsening	PM2.5
Juncos	9	174	338	6	→ stable	Ozone
Mayagnez	11	39	341	0	↓ improving	Ozone
Ponce	3	82	317	0	↓ improving	PM2.5
San Juan	7	10	41	0	↓ improving	Ozone