Daily Air Quality Index summaries from EPA monitors in Platte, Missouri, 1980–2005.
61%
Good days in 2005
46
Median daily AQI, 2005
33
Days above 100 in 2005
214
Days with an AQI in 2005 (of 365)
In 2005, EPA reported a daily Air Quality Index (AQI) for Platte, Missouri on 214 days. 130 of those days (61%) were in the Good range, and the median daily AQI was 46. That median is lower than the typical monitored county in Missouri (median 50 across 17 counties), and about the same as the typical monitored U.S. county (44). The main pollutant was ozone on 214 days. Across the years with fuller monitoring, the share of Good days fell: an average of 79% in 1980–1982 versus 76% in 2003–2005.
EPA did not report an AQI for every day of 2005 here (214 of 365 days). Figures describe monitored days only; seasonal monitoring (for example, ozone measured only in warmer months) can make a county look cleaner or dirtier than a full-year record would.
The most recent year with data for this county is 2005; EPA's files for 2006–2025 contain no row for it, which usually means its monitors stopped reporting.
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, 2005
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
214
100%
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
2005
214
130
51
29
4
0
0
46
112
169
Ozone
2004
306
261
42
3
0
0
0
36
61
108
Ozone
2003
343
286
48
8
1
0
0
33
77
166
Ozone
2002
365
293
51
19
2
0
0
31
77
166
Ozone
2001
365
295
57
11
2
0
0
32
71
166
Ozone
2000
366
285
60
17
4
0
0
35
77
172
Ozone
1999
364
298
52
14
0
0
0
36
71
143
Ozone
1998
360
278
69
8
5
0
0
36
80
179
Ozone
1997
365
300
51
8
6
0
0
34
74
177
Ozone
1996
364
306
48
9
1
0
0
35
67
154
Ozone
1995
365
299
42
18
6
0
0
35
77
185
Ozone
1994
352
276
61
14
1
0
0
32
77
154
Ozone
1993
363
323
36
4
0
0
0
31
54
147
Ozone
1992
366
324
37
4
1
0
0
30
52
192
Ozone
1991
354
306
35
11
2
0
0
32
64
151
Ozone
1990
351
334
15
1
1
0
0
29
44
190
Ozone
1989
365
327
34
4
0
0
0
34
53
140
Ozone
1988
354
282
48
17
7
0
0
32
90
174
Ozone
1987
362
279
66
16
1
0
0
34
84
154
Ozone
1986
365
309
45
10
1
0
0
36
64
179
Ozone
1985
365
296
53
14
2
0
0
36
67
169
Ozone
1984
366
300
43
13
9
1
0
35
84
203
Ozone
1983
361
306
36
17
2
0
0
29
80
169
Ozone
1982
356
278
73
4
1
0
0
38
61
161
Ozone
1981
356
303
40
8
5
0
0
26
67
179
Ozone
1980
294
219
42
23
8
2
0
24
112
210
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.
