Spokane Air Quality in August
Across 2019–2025, Spokane's August air quality had a median AQI of 51 (Moderate) over 217 monitored days in the Spokane-Spokane Valley, WA area. 8.3% of August days (18 of 217) reached Unhealthy for Sensitive Groups or worse, and fine particulate matter (PM2.5) set the daily AQI on 53.5% of days. The cleanest August on record here was 2020 (median AQI 45, 0 days above 100) and the worst was 2021 (median 70, 8 days above 100, peak AQI 223).
- Good: 47.9%
- Moderate: 43.8%
- Unhealthy for Sensitive Groups: 2.8%
- Unhealthy or worse: 5.5%
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How is the air in Spokane in August?
Moderate on a typical day: median AQI 51 across 2019–2025, with 8.3% of August days above AQI 100. Fine particulate matter (PM2.5) is the main driver.
- ✓47.9% of August days were Good (AQI 0–50), 43.8% Moderate (51–100).
- ✓18 days of 217 reached AQI 101+; the August peak was 447.
- ✓Best August: 2020; worst August: 2021.
Frequently asked questions
What is the air quality like in Spokane in August?▾
Across 2019–2025, the median daily AQI in Spokane in August was 51 (Moderate). 47.9% of days were Good, 43.8% Moderate, and 8.3% reached Unhealthy for Sensitive Groups or worse, based on 217 monitored days in EPA's Air Quality System.
Is August a good time for outdoor exercise in Spokane?▾
A typical August day in Spokane is Moderate (median AQI 51): outdoor exercise is acceptable for most people, but unusually sensitive individuals should watch for symptoms, and about 1 day in 12 of August days (8.3%) reached AQI 101+ — the level at which EPA advises people with asthma, children and older adults to shorten hard outdoor exertion.
Which pollutant causes Spokane's August air quality problems?▾
Fine particulate matter (PM2.5) set the daily AQI on 53.5% of August days in Spokane. The highest August AQI recorded in 2019–2025 was 447 (Hazardous), in 2021.
Spokane August air quality, year by year
Spokane August air quality by year (Spokane-Spokane Valley, WA, EPA AQS daily AQI)
| Year | Days monitored | Median AQI | Days above 100 | Peak AQI | Main pollutant |
|---|---|---|---|---|---|
| 2019 | 31 | 45 | 2 | 146 | O3 |
| 2020cleanest | 31 | 45 | 0 | 64 | O3 |
| 2021worst | 31 | 70 | 8 | 223 | PM2.5 |
| 2022 | 31 | 49 | 0 | 74 | O3 |
| 2023 | 31 | 65 | 7 | 447 | PM2.5 |
| 2024 | 31 | 55 | 0 | 82 | PM2.5 |
| 2025 | 31 | 52 | 1 | 127 | PM2.5 |
What August air means in Spokane
A typical August day in Spokane is Moderate (median AQI 51): outdoor exercise is acceptable for most people, but unusually sensitive individuals should watch for symptoms, and about 1 day in 12 of August days (8.3%) reached AQI 101+ — the level at which EPA advises people with asthma, children and older adults to shorten hard outdoor exertion.
August's median AQI of 51 is above Spokane's whole-year median of 47, making it one of the area's dirtier periods. Nationally, the median August AQI across every EPA metro area (104,152 metro-days, 2019–2025) is 45, so Spokane runs above the national August norm; 8.3% of its August days topped AQI 100 versus 3.5% nationally (above average).
August is part of Spokane's summer season (June, July, August); the summer page pools all three months.
Activity-specific thresholds: running, cycling, kids' sports.
Right now in Spokane
The latest EPA AirNow observation puts Spokane's AQI at 35 (PM2.5). The figures above are multi-year month statistics, not today's reading.
View current Spokane air quality →Source: EPA Air Quality System (AQS) pre-generated Daily AQI by CBSA files — daily AQI by CBSA (Spokane-Spokane Valley, 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.