Tacoma Air Quality in 2020
In 2020, Tacoma's air quality (Seattle-Tacoma-Bellevue, WA area) had a median daily AQI of 49 (Good) across 366 monitored days. 14 days (3.8%) reached Unhealthy for Sensitive Groups or worse, 196 were Good, and the year's peak AQI was 299 (Very Unhealthy). Fine particulate matter (PM2.5) set the daily AQI on 256 of those days. The cleanest month of 2020 was May (median AQI 44, 0 days above 100) and the worst was September (median 54, 11 days above 100, peak 299).
- Good: 53.6%
- Moderate: 42.6%
- Unhealthy for Sensitive Groups: 1.4%
- Unhealthy or worse: 2.5%
Extra Protection for Tacoma Homes
Air quality in Tacoma is moderate (AQI 52), with fine particles (PM2.5) the main concern. A True-HEPA purifier gives sensitive groups — kids, seniors and anyone with asthma or allergies — cleaner air indoors on days like today.
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How was Tacoma's air quality in 2020?
Good on a typical day: median AQI 49, with 14 days above AQI 100 out of 366 monitored — the 6th cleanest of 7 years on record for the area.
- ✓Peak AQI in 2020: 299 (Very Unhealthy).
- ✓Fine particulate matter (PM2.5) was the main pollutant on 256 days.
- ✓Cleanest month: May; worst: September.
Frequently asked questions
What was the average AQI in Tacoma in 2020?▾
EPA's Air Quality System puts Tacoma's (Seattle-Tacoma-Bellevue, WA) median daily AQI for 2020 at 49, which is Good. 14 days were Unhealthy for Sensitive Groups or worse and the year's highest AQI was 299.
Which month had the worst air quality in Tacoma in 2020?▾
The cleanest month of 2020 was May (median AQI 44, 0 days above 100) and the worst was September (median 54, 11 days above 100, peak 299).
Was 2020 a good or bad year for Tacoma's air?▾
Among the 7 years EPA has published for the area (2019–2025), 2020 ranks 6th cleanest by days above AQI 100. 2020's median of 49 is in line with the area's typical annual median of 49.
Tacoma month by month in 2020
Tacoma air quality month by month, 2020 (Seattle-Tacoma-Bellevue, WA, EPA AQS daily AQI)
| Month | Days monitored | Median AQI | Days above 100 | Peak AQI | Main pollutant |
|---|---|---|---|---|---|
| January | 31 | 46 | 0 | 72 | PM2.5 |
| February | 29 | 55 | 0 | 99 | PM2.5 |
| March | 31 | 52 | 0 | 81 | PM2.5 |
| April | 30 | 52 | 0 | 64 | PM2.5 |
| Maycleanest | 31 | 44 | 0 | 61 | O3 |
| June | 30 | 37 | 1 | 155 | O3 |
| July | 31 | 41 | 1 | 144 | PM2.5 |
| August | 31 | 44 | 1 | 103 | PM2.5 |
| Septemberworst | 30 | 54 | 11 | 299 | PM2.5 |
| October | 31 | 53 | 0 | 81 | PM2.5 |
| November | 30 | 53 | 0 | 87 | PM2.5 |
| December | 31 | 57 | 0 | 97 | PM2.5 |
How 2020 compares
Among the 7 years EPA has published for the area (2019–2025), 2020 ranks 6th cleanest by days above AQI 100.
2020's median of 49 is in line with the area's typical annual median of 49.
Activity-specific thresholds: running, cycling, kids' sports.
Right now in Tacoma
The latest EPA AirNow observation puts Tacoma's AQI at 52 (PM2.5). The figures above are multi-year annual statistics, not today's reading.
View current Tacoma air quality →Source: EPA Air Quality System (AQS) pre-generated Daily AQI by CBSA files — daily AQI by CBSA (Seattle-Tacoma-Bellevue, WA), 2019–2025. Daily AQI per CBSA is the highest AQI reported by any monitor in the area that day; the defining parameter is the pollutant that set it. Month and season statistics pool every such day in the period across all years listed. Retrieved 2026-09-09.