Daily Air Quality Index summaries from EPA monitors in Greene, Pennsylvania, 1997–2025.
78%
Good days in 2025
40
Median daily AQI, 2025
1
Days above 100 in 2025
365
Days with an AQI in 2025 (of 365)
In 2025, EPA reported a daily Air Quality Index (AQI) for Greene, Pennsylvania on 365 days. 284 of those days (78%) were in the Good range, and the median daily AQI was 40. That median is about the same as the typical monitored county in Pennsylvania (median 40 across 38 counties), and about the same as the typical monitored U.S. county (40). The main pollutant was ozone on 267 days. Across the years with fuller monitoring, the share of Good days rose: an average of 38% in 1998–2000 versus 79% in 2023–2025.
Years with fewer than 120 monitored days (1997) are shown in the table but left out of comparisons and trend statements.
How the days broke down each year
Each bar is one year. The colored segments show the share of monitored days that fell in each AQI category.
Good
Moderate
Unhealthy for Sensitive Groups
Unhealthy
Very Unhealthy
Hazardous
Typical and high-end AQI over time
The median is the middle day of the year. The 90th percentile is the level that only the highest 10% of days exceeded.
Median daily AQI
90th-percentile daily AQI
Main pollutant by day, 2025
On each monitored day, the AQI reflects whichever measured pollutant had the highest index. This counts how many days each pollutant set the AQI. A pollutant that was not measured here cannot appear.
Pollutant
Days as main pollutant
Share of monitored days
Ozone
267
73%
Fine particles (PM2.5)
98
27%
Year-by-year data
Annual AQI summary by year
Year
Days with AQI
Good
Moderate
Unhealthy for Sensitive Groups
Unhealthy
Very Unhealthy
Hazardous
Median AQI
90th pct.
Max AQI
Main pollutant
2025
365
284
80
1
0
0
0
40
61
105
Ozone
2024
230
196
34
0
0
0
0
38
53
87
Ozone
2023
302
219
81
2
0
0
0
44
64
108
Ozone
2022
294
231
63
0
0
0
0
42
56
100
Ozone
2021
340
232
107
1
0
0
0
42
62
113
PM2.5
2020
359
294
64
1
0
0
0
39
53
101
Ozone
2019
349
294
55
0
0
0
0
38
54
71
Ozone
2018
360
288
72
0
0
0
0
39
55
100
Ozone
2017
356
255
101
0
0
0
0
42
58
93
Ozone
2016
355
297
57
1
0
0
0
39
56
105
Ozone
2015
362
301
57
4
0
0
0
37
61
115
Ozone
2014
362
327
33
2
0
0
0
39
50
108
Ozone
2013
340
305
33
2
0
0
0
38
51
126
Ozone
2012
259
181
65
13
0
0
0
42
77
143
Ozone
2011
214
175
38
1
0
0
0
42
61
112
Ozone
2010
213
146
58
9
0
0
0
45
80
150
Ozone
2009
214
174
39
1
0
0
0
42
64
112
Ozone
2008
208
155
47
6
0
0
0
44
77
147
Ozone
2007
215
109
78
28
0
0
0
50
105
133
Ozone
2006
214
130
72
12
0
0
0
47
87
150
Ozone
2005
215
113
72
28
2
0
0
49
112
172
Ozone
2004
215
165
41
9
0
0
0
42
71
140
Ozone
2003
246
165
71
7
3
0
0
44
84
200
Ozone
2002
215
117
60
32
5
1
0
49
115
203
Ozone
2001
215
103
70
31
11
0
0
51
133
169
Ozone
2000
215
104
81
24
5
1
0
51
115
202
Ozone
1999
211
71
80
43
16
1
0
74
147
202
Ozone
1998
135
45
47
28
14
1
0
74
154
202
Ozone
1997
113
42
37
25
8
1
0
67
143
205
Ozone
What this data can and can’t tell you
It is a county-level summary. EPA reports one AQI per day for the county, based on the monitors operating there. Air at a particular street, school or home can differ, especially near roads, industry or wildfire smoke.
It is not a health assessment. The AQI is EPA’s scale for communicating daily air quality. A county’s history can’t tell you what the health risk is for any particular person. For daily conditions and health guidance, see AirNow.
Rules change over time. EPA has revised AQI breakpoints, most recently for fine particles in 2024, so some year-to-year change can reflect the scale rather than the air.
Counties in Pennsylvania with a similar median AQI in 2025
