EnviroNearby

Garfield County, Washington air quality history

Daily Air Quality Index summaries from EPA monitors in Garfield, Washington, 2017–2025.

93%
Good days in 2025
19
Median daily AQI, 2025
0
Days above 100 in 2025
347
Days with an AQI in 2025 (of 365)

In 2025, EPA reported a daily Air Quality Index (AQI) for Garfield, Washington on 347 days. 321 of those days (93%) were in the Good range, and the median daily AQI was 19. That median is lower than the typical monitored county in Washington (median 28 across 30 counties), and lower than the typical monitored U.S. county (40). The main pollutant was fine particles (PM2.5) on 347 days. Across the years with fuller monitoring, the share of Good days rose: an average of 85% in 2017–2019 versus 92% in 2023–2025.

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.

Share of monitored days in each AQI category, by year0%25%50%75%100%2017: Good 144 of 183 days2017: Moderate 33 of 183 days2017: Unhealthy for Sensitive Groups 3 of 183 days2017: Unhealthy 3 of 183 days20172018: Good 310 of 364 days2018: Moderate 50 of 364 days2018: Unhealthy for Sensitive Groups 3 of 364 days2018: Unhealthy 1 of 364 days20182019: Good 330 of 358 days2019: Moderate 28 of 358 days20192020: Good 305 of 335 days2020: Moderate 21 of 335 days2020: Unhealthy for Sensitive Groups 2 of 335 days2020: Unhealthy 5 of 335 days2020: Very Unhealthy 2 of 335 days20202021: Good 284 of 334 days2021: Moderate 44 of 334 days2021: Unhealthy for Sensitive Groups 1 of 334 days2021: Unhealthy 4 of 334 days2021: Very Unhealthy 1 of 334 days20212022: Good 263 of 301 days2022: Moderate 34 of 301 days2022: Unhealthy for Sensitive Groups 2 of 301 days2022: Unhealthy 2 of 301 days20222023: Good 340 of 365 days2023: Moderate 23 of 365 days2023: Unhealthy 1 of 365 days2023: Very Unhealthy 1 of 365 days20232024: Good 314 of 348 days2024: Moderate 34 of 348 days20242025: Good 321 of 347 days2025: Moderate 26 of 347 days2025
  • 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 and 90th-percentile daily AQI, by year0501002017: 90th percentile AQI 662018: 90th percentile AQI 552019: 90th percentile AQI 482020: 90th percentile AQI 482021: 90th percentile AQI 622022: 90th percentile AQI 542023: 90th percentile AQI 412024: 90th percentile AQI 502025: 90th percentile AQI 452017: Median AQI 282018: Median AQI 202019: Median AQI 232020: Median AQI 192021: Median AQI 192022: Median AQI 212023: Median AQI 172024: Median AQI 172025: Median AQI 19201720182019202020212022202320242025
  • 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.

PollutantDays as main pollutantShare of monitored days
Fine particles (PM2.5)347100%

Year-by-year data

Annual AQI summary by year
YearDays with AQIGoodModerateUnhealthy for Sensitive GroupsUnhealthyVery UnhealthyHazardousMedian AQI90th pct.Max AQIMain pollutant
2025347321260000194597PM2.5
2024348314340000175085PM2.5
20233653402301101741244PM2.5
20223012633422002154161PM2.5
20213342844414101962224PM2.5
20203353052125201948252PM2.5
2019358330280000234867PM2.5
20183643105031002055172PM2.5
20171831443333002866190PM2.5

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 Washington with a similar median AQI in 2025

All monitored counties in Washington

Source: U.S. EPA AirData, “Annual AQI by County” files for 2017–2025 (EPA download page). EPA file dates: 2026-06-26. Imported into EnviroNearby November 5, 2026. How we use this data · Report a problem