Bad Air Days in Matanuska-Susitna, Alaska: 2 a Year
2 bad air days a year
About the middle of monitored US counties. Ranked 454 of 996 monitored counties, where 1 is worst.
What makes them bad: mostly particles: smoke and dust (100% particle days).
Which months to watch
- J
- F
- M
- A
- M
- J
- J
- A
- S
- O
- N
- D
Most bad days here fall in January and April and November. Averaged over 2016 to 2025.
What actually helps here
- Bad air days are rare here. A standard furnace filter is enough; no purifier needed for outdoor air.
- On the odd bad day, check AirNow and keep windows shut.
The record for Matanuska-Susitna
The worst recent year was 2017, with 5 bad days on 365 monitored days.
| Date | AQI | Main pollutant |
|---|---|---|
| 2021-01-01 | 163 | PM2.5 |
| 2017-01-01 | 157 | PM2.5 |
| 2018-11-16 | 151 | PM10 |
| 2025-04-16 | 141 | PM10 |
| 2016-11-21 | 128 | PM10 |
Most days, not the worst ones
Across 3,580 monitored days from 2016 to 2025, the air in Matanuska-Susitna rated Good on 85% of them, more often than the 72% typical of monitored counties, and Moderate on 14%. The median day sat at AQI 20; one day in ten went above 55.
The pollutant setting the AQI on an ordinary day here:
- fine particles (PM2.5)69%2,466 days
- ozone17%607 days
- coarse dust (PM10)14%507 days
Every recent year on file
| Year | Days monitored | Good | Moderate | Over 100 | Over 150 | Median AQI | Highest AQI |
|---|---|---|---|---|---|---|---|
| 2025* | 352 | 322 | 28 | 2 | 0 | 9 | 141 |
| 2024 | 359 | 331 | 28 | 0 | 0 | 15 | 95 |
| 2023 | 358 | 317 | 40 | 1 | 0 | 14 | 102 |
| 2022 | 341 | 301 | 40 | 0 | 0 | 12 | 89 |
| 2021 | 354 | 307 | 44 | 3 | 1 | 15 | 163 |
| 2020 | 359 | 317 | 41 | 1 | 0 | 17 | 103 |
| 2019 | 361 | 262 | 96 | 3 | 0 | 25 | 127 |
| 2018 | 365 | 308 | 53 | 4 | 1 | 29 | 151 |
| 2017 | 365 | 296 | 64 | 5 | 1 | 32 | 157 |
| 2016 | 366 | 282 | 80 | 4 | 0 | 34 | 128 |
| 2015 | 365 | 269 | 85 | 11 | 1 | 31 | 155 |
| 2014 | 365 | 254 | 100 | 11 | 2 | 33 | 231 |
| 2013 | 365 | 288 | 73 | 4 | 0 | 29 | 114 |
| 2012 | 366 | 255 | 106 | 5 | 0 | 36 | 127 |
| 2011 | 362 | 261 | 98 | 3 | 1 | 38 | 241 |
| 2010 | 317 | 277 | 37 | 3 | 0 | 17 | 118 |
*2025 may be a partial year in EPA's file.
Alaska compared
- Fairbanks North Star37/yr
- Anchorage1/yr
- Bethel1/yr
- Juneauunder 1/yr
- North Slopethin data
- Kenai Peninsulathin data
- Aleutians Eastthin data
- Denali0/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.