Indianapolis Air Quality in April
Across 2019–2025, Indianapolis's April air quality had a median AQI of 54 (Moderate) over 210 monitored days in the Indianapolis-Carmel-Anderson, IN area. 0.5% of April days (1 of 210) reached Unhealthy for Sensitive Groups or worse, and fine particulate matter (PM2.5) set the daily AQI on 67.1% of days. The cleanest April on record here was 2024 (median AQI 48, 0 days above 100) and the worst was 2021 (median 60, 1 day above 100, peak AQI 114).
- Good: 36.7%
- Moderate: 62.9%
- Unhealthy for Sensitive Groups: 0.5%
- Unhealthy or worse: 0.0%
Extra Protection for Indianapolis Homes
Air quality in Indianapolis is moderate (AQI 55), 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 is the air in Indianapolis in April?
Moderate on a typical day: median AQI 54 across 2019–2025, with 0.5% of April days above AQI 100. Fine particulate matter (PM2.5) is the main driver.
- ✓36.7% of April days were Good (AQI 0–50), 62.9% Moderate (51–100).
- ✓1 day of 210 reached AQI 101+; the April peak was 114.
- ✓Best April: 2024; worst April: 2021.
Frequently asked questions
What is the air quality like in Indianapolis in April?▾
Across 2019–2025, the median daily AQI in Indianapolis in April was 54 (Moderate). 36.7% of days were Good, 62.9% Moderate, and 0.5% reached Unhealthy for Sensitive Groups or worse, based on 210 monitored days in EPA's Air Quality System.
Is April a good time for outdoor exercise in Indianapolis?▾
A typical April day in Indianapolis is Moderate (median AQI 54): outdoor exercise is acceptable for most people, but unusually sensitive individuals should watch for symptoms, and fewer than 1% of April days reached AQI 101+ — the level at which EPA advises people with asthma, children and older adults to shorten hard outdoor exertion.
Which pollutant causes Indianapolis's April air quality problems?▾
Fine particulate matter (PM2.5) set the daily AQI on 67.1% of April days in Indianapolis. The highest April AQI recorded in 2019–2025 was 114 (Unhealthy for Sensitive Groups), in 2021.
Indianapolis April air quality, year by year
Indianapolis April air quality by year (Indianapolis-Carmel-Anderson, IN, EPA AQS daily AQI)
| Year | Days monitored | Median AQI | Days above 100 | Peak AQI | Main pollutant |
|---|---|---|---|---|---|
| 2019 | 30 | 53 | 0 | 95 | PM2.5 |
| 2020 | 30 | 58 | 0 | 71 | PM2.5 |
| 2021worst | 30 | 60 | 1 | 114 | PM2.5 |
| 2022 | 30 | 52 | 0 | 69 | PM2.5 |
| 2023 | 30 | 62 | 0 | 97 | PM2.5 |
| 2024cleanest | 30 | 48 | 0 | 74 | O3 |
| 2025 | 30 | 50 | 0 | 73 | PM2.5 |
What April air means in Indianapolis
A typical April day in Indianapolis is Moderate (median AQI 54): outdoor exercise is acceptable for most people, but unusually sensitive individuals should watch for symptoms, and fewer than 1% of April days reached AQI 101+ — the level at which EPA advises people with asthma, children and older adults to shorten hard outdoor exertion.
April's median AQI of 54 is in line with Indianapolis's whole-year median of 56, so this period is neither a clean nor a dirty stretch for the area. Nationally, the median April AQI across every EPA metro area (100,677 metro-days, 2019–2025) is 44, so Indianapolis runs above the national April norm; 0.5% of its April days topped AQI 100 versus 0.7% nationally (about the same).
April is part of Indianapolis's spring season (March, April, May); the spring page pools all three months.
Activity-specific thresholds: running, cycling, kids' sports.
Right now in Indianapolis
The latest EPA AirNow observation puts Indianapolis's AQI at 55 (PM2.5). The figures above are multi-year month statistics, not today's reading.
View current Indianapolis air quality →Source: EPA Air Quality System (AQS) pre-generated Daily AQI by CBSA files — daily AQI by CBSA (Indianapolis-Carmel-Anderson, IN), 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.