Madison Air Quality in October
Across 2019–2025, Madison's October air quality had a median AQI of 37 (Good) over 217 monitored days in the Madison, WI area. 0.0% of October days (0 of 217) reached Unhealthy for Sensitive Groups or worse, and fine particulate matter (PM2.5) set the daily AQI on 67.3% of days. The cleanest October on record here was 2025 (median AQI 33, 0 days above 100) and the worst was 2022 (median 47, 0 days above 100, peak AQI 91).
- Good: 77.9%
- Moderate: 22.1%
- Unhealthy for Sensitive Groups: 0.0%
- Unhealthy or worse: 0.0%
Improve Indoor Air Quality
Even with good outdoor air in Madison, indoor PM2.5, dust and allergens build up. A True-HEPA purifier keeps a bedroom or office consistently clean.
Recommended: Levoit Core 400S — True HEPA · CADR ~141 CFM · rooms up to 219 sq ft
As an Amazon Associate, we earn from qualifying purchases.
How is the air in Madison in October?
Good on a typical day: median AQI 37 across 2019–2025, with 0.0% of October days above AQI 100. Fine particulate matter (PM2.5) is the main driver.
- ✓77.9% of October days were Good (AQI 0–50), 22.1% Moderate (51–100).
- ✓0 days of 217 reached AQI 101+; the October peak was 91.
- ✓Best October: 2025; worst October: 2022.
Frequently asked questions
What is the air quality like in Madison in October?▾
Across 2019–2025, the median daily AQI in Madison in October was 37 (Good). 77.9% of days were Good, 22.1% Moderate, and 0.0% reached Unhealthy for Sensitive Groups or worse, based on 217 monitored days in EPA's Air Quality System.
Is October a good time for outdoor exercise in Madison?▾
A typical October day in Madison sits in the Good range (median AQI 37), so running, cycling and children's outdoor play are fine for everyone on most days; fewer than 1% of October days reached AQI 101+ in 2019–2025.
Which pollutant causes Madison's October air quality problems?▾
Fine particulate matter (PM2.5) set the daily AQI on 67.3% of October days in Madison. The highest October AQI recorded in 2019–2025 was 91 (Moderate), in 2022.
Madison October air quality, year by year
Madison October air quality by year (Madison, WI, EPA AQS daily AQI)
| Year | Days monitored | Median AQI | Days above 100 | Peak AQI | Main pollutant |
|---|---|---|---|---|---|
| 2019 | 31 | 35 | 0 | 59 | PM2.5 |
| 2020 | 31 | 37 | 0 | 58 | PM2.5 |
| 2021 | 31 | 38 | 0 | 75 | PM2.5 |
| 2022worst | 31 | 47 | 0 | 91 | PM2.5 |
| 2023 | 31 | 34 | 0 | 71 | PM2.5 |
| 2024 | 31 | 37 | 0 | 64 | O3 |
| 2025cleanest | 31 | 33 | 0 | 80 | PM2.5 |
What October air means in Madison
A typical October day in Madison sits in the Good range (median AQI 37), so running, cycling and children's outdoor play are fine for everyone on most days; fewer than 1% of October days reached AQI 101+ in 2019–2025.
October's median AQI of 37 is below Madison's whole-year median of 45, making it one of the area's cleaner periods. Nationally, the median October AQI across every EPA metro area (102,872 metro-days, 2019–2025) is 38, so Madison runs in line with the national October norm; 0.0% of its October days topped AQI 100 versus 1.3% nationally (below average).
October is part of Madison's fall season (September, October, November); the fall page pools all three months.
Activity-specific thresholds: running, cycling, kids' sports.
Right now in Madison
The latest EPA AirNow observation puts Madison's AQI at 49 (PM2.5). The figures above are multi-year month statistics, not today's reading.
View current Madison air quality →Source: EPA Air Quality System (AQS) pre-generated Daily AQI by CBSA files — daily AQI by CBSA (Madison, WI), 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.