Madison Air Quality in March
Across 2019–2025, Madison's March air quality had a median AQI of 42 (Good) over 217 monitored days in the Madison, WI area. 0.0% of March days (0 of 217) reached Unhealthy for Sensitive Groups or worse, and fine particulate matter (PM2.5) set the daily AQI on 91.7% of days. The cleanest March on record here was 2025 (median AQI 32, 0 days above 100) and the worst was 2021 (median 53, 0 days above 100, peak AQI 86).
- Good: 62.7%
- Moderate: 37.3%
- Unhealthy for Sensitive Groups: 0.0%
- Unhealthy or worse: 0.0%
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How is the air in Madison in March?
Good on a typical day: median AQI 42 across 2019–2025, with 0.0% of March days above AQI 100. Fine particulate matter (PM2.5) is the main driver.
- ✓62.7% of March days were Good (AQI 0–50), 37.3% Moderate (51–100).
- ✓0 days of 217 reached AQI 101+; the March peak was 86.
- ✓Best March: 2025; worst March: 2021.
Frequently asked questions
What is the air quality like in Madison in March?▾
Across 2019–2025, the median daily AQI in Madison in March was 42 (Good). 62.7% of days were Good, 37.3% Moderate, and 0.0% reached Unhealthy for Sensitive Groups or worse, based on 217 monitored days in EPA's Air Quality System.
Is March a good time for outdoor exercise in Madison?▾
A typical March day in Madison sits in the Good range (median AQI 42), so running, cycling and children's outdoor play are fine for everyone on most days; fewer than 1% of March days reached AQI 101+ in 2019–2025.
Which pollutant causes Madison's March air quality problems?▾
Fine particulate matter (PM2.5) set the daily AQI on 91.7% of March days in Madison. The highest March AQI recorded in 2019–2025 was 86 (Moderate), in 2021.
Madison March air quality, year by year
Madison March air quality by year (Madison, WI, EPA AQS daily AQI)
| Year | Days monitored | Median AQI | Days above 100 | Peak AQI | Main pollutant |
|---|---|---|---|---|---|
| 2019 | 31 | 50 | 0 | 78 | PM2.5 |
| 2020 | 31 | 49 | 0 | 67 | PM2.5 |
| 2021worst | 31 | 53 | 0 | 86 | PM2.5 |
| 2022 | 31 | 38 | 0 | 81 | PM2.5 |
| 2023 | 31 | 47 | 0 | 75 | PM2.5 |
| 2024 | 31 | 34 | 0 | 60 | PM2.5 |
| 2025cleanest | 31 | 32 | 0 | 80 | PM2.5 |
What March air means in Madison
A typical March day in Madison sits in the Good range (median AQI 42), so running, cycling and children's outdoor play are fine for everyone on most days; fewer than 1% of March days reached AQI 101+ in 2019–2025.
March's median AQI of 42 is in line with Madison's whole-year median of 45, so this period is neither a clean nor a dirty stretch for the area. Nationally, the median March AQI across every EPA metro area (102,455 metro-days, 2019–2025) is 42, so Madison runs in line with the national March norm; 0.0% of its March days topped AQI 100 versus 0.4% nationally (about the same).
March is part of Madison's spring season (March, April, May); the spring 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.