Bad Air Days in Santa Cruz County, Arizona: 3 a Year
3 bad air days a year
About the middle of monitored US counties. Ranked 376 of 996 monitored counties, where 1 is worst.
What makes them bad: mostly particles: smoke and dust (100% particle days).
The bad-air season here
- J
- F
- M
- A
- M
- J
- J
- A
- S
- O
- N
- D
Most bad days here fall in December and January. Averaged over 2016 to 2025.
Is a purifier worth it here?
- Particles (wildfire smoke, dust) cause enough bad days here to matter. A HEPA purifier sized to your bedroom removes them; run it with windows shut on bad days.
Better or worse than it was
In 2000 to 2009 this county averaged 20 bad days a year; in 2016 to 2025, 3. The air has improved. The worst recent year was 2024, with 9 bad days on 361 monitored days.
| Date | AQI | Main pollutant |
|---|---|---|
| 2024-01-01 | 494 | PM2.5 |
| 2016-01-01 | 209 | PM2.5 |
| 2017-12-25 | 198 | PM2.5 |
| 2018-01-01 | 194 | PM2.5 |
| 2025-01-01 | 187 | PM2.5 |
An ordinary day in Santa Cruz
Across 3,615 monitored days from 2016 to 2025, the air in Santa Cruz County rated Good on 61% of them, less often than the 72% typical of monitored counties, and Moderate on 38%. The median day sat at AQI 43; one day in ten went above 68.
The pollutant setting the AQI on an ordinary day here:
- fine particles (PM2.5)83%3,010 days
- coarse dust (PM10)17%605 days
Every recent year on file
| Year | Days monitored | Good | Moderate | Over 100 | Over 150 | Median AQI | Highest AQI |
|---|---|---|---|---|---|---|---|
| 2025* | 364 | 190 | 171 | 3 | 1 | 49 | 187 |
| 2024 | 361 | 213 | 139 | 9 | 1 | 43 | 494 |
| 2023 | 358 | 265 | 92 | 1 | 0 | 37 | 145 |
| 2022 | 357 | 220 | 136 | 1 | 0 | 43 | 138 |
| 2021 | 360 | 169 | 189 | 2 | 1 | 52 | 171 |
| 2020 | 360 | 208 | 147 | 5 | 1 | 44 | 170 |
| 2019 | 362 | 250 | 110 | 2 | 0 | 39 | 120 |
| 2018 | 365 | 252 | 111 | 2 | 1 | 39 | 194 |
| 2017 | 365 | 236 | 125 | 4 | 2 | 40 | 198 |
| 2016 | 363 | 193 | 169 | 1 | 1 | 48 | 209 |
| 2015 | 365 | 261 | 101 | 3 | 0 | 38 | 135 |
| 2014 | 365 | 249 | 112 | 4 | 2 | 38 | 223 |
| 2013 | 344 | 228 | 111 | 5 | 2 | 41 | 159 |
| 2012 | 337 | 222 | 114 | 1 | 0 | 42 | 107 |
| 2011 | 352 | 209 | 141 | 2 | 0 | 44 | 104 |
| 2010 | 165 | 91 | 68 | 6 | 0 | 47 | 119 |
*2025 may be a partial year in EPA's file.
Elsewhere in Arizona
- Maricopa County89/yr
- Pinal County53/yr
- Gila County14/yr
- Pima County9/yr
- Yuma County9/yr
- Cochise County3/yr
- La Paz County2/yr
- Coconino County2/yr
How this is counted
A bad air day is a day the county's daily AQI from EPA AirData went above 100, the level where EPA tells children, older adults and people with asthma or heart disease to cut back outdoors. Monitors do not run every day, so yearly counts are scaled to 365 days. This is the record, not today's air: for that, check AirNow. More on the method in how the county numbers are made, on the AQI 100 line in what counts as a bad air day.