Right now: Indianapolis is at 35, good.
Is the air safe to breathe in Indianapolis today?
In Indianapolis, BreatheCheck reads 35 as Go. The cutoffs: go below 101, keep it short and easy from 101 to 150, move it indoors above 150. These are our own thresholds, drawn on the EPA bands — EPA itself classifies 101–150 as Unhealthy for Sensitive Groups and does not tell you how long to stay out.
Go AQI 0–100
Normal outdoor plans. No change needed.
Short & unloaded AQI 101–150
A 20-minute dog walk, not a 2.5-hour run. Keep it brief and easy.
Don’t go AQI 151+
Move it indoors. Above 200 that becomes everyone, not just sensitive groups.
Above 200 this stops being a personal call: everyone indoors.
Duration and intensity are two separate dials
| Under 20 min | 20–60 min | Over an hour | |
|---|---|---|---|
| Easy | Go | Go | Go |
| Moderate | Go | Go | Go |
| Hard | Go | Go | Go |
Go Every combination lands the same way at this reading — a hard hour is no different from an easy twenty minutes. The two dials separate above 80.
Where people actually draw the line
All the thresholds people reported, and who reported them
- 60 Asthmatic runnerone runner’s own 156-run log
- 75–100 Daycare / schoolparents and staff in one r/toddlers thread, Aug 2025 — not a published rule
- 100 Parentcommunity-reported, escalating at 150 and 200
- 110 Runnercommunity-reported
If you’re staying in, filter the room you’re actually in
A freight crossroads waiting on the weather
Freight is the constant in Indianapolis. Four interstates converge on the I-465 beltway and the metro works as a national distribution and warehousing point, which keeps diesel exhaust and nitrogen oxides entering the air at a fairly steady rate. The city’s own contribution barely varies from week to week. What varies is whether anything is carrying it away.
The landscape does not decide that. Marion County sits on the Tipton Till Plain, glacial ground where the difference between the high points and the low ones runs on the order of ten to thirty feet and the whole surface tilts gently toward the White River. A cold pool here has to be manufactured by the weather rather than held by a valley wall, and in winter the weather obliges: a stationary high over Indiana brings light wind and a low-level inversion, and what goes up under that lid stays under it until the pattern breaks. Summer swaps the pollutant without changing the arrangement, heat and sunlight cooking ozone out of the same traffic through the afternoon.
The thing a single figure cannot show is duration. A stagnant winter high can hold the same reading in place for four days running, and four flat days at one level is a different week from one rough afternoon that has averaged back to ordinary by Tuesday.
Where this number sits
Of the 121 US metros reporting to us right now, Indianapolis is number 77 and the highest of the 2 we track in Indiana. The pollutant driving it today is O3.
Nearby metros we also measure, and what they read at the same hour:
- Cincinnati, OH — 99 miles away, AQI 37
- Louisville, KY — 107 miles away, AQI 44
- Fort Wayne, IN — 108 miles away, AQI 31
- Lexington, KY — 153 miles away, AQI 35
Where this reading comes from
AirNow’s Indianapolis reporting area, about 2 miles from the metro centre.
What has air quality in Indianapolis actually been?
3 of the 30 days we have recorded so far went above AQI 100.
| Date | Daily max AQI | EPA band | Hours read |
|---|---|---|---|
| 39 | Good | 23 | |
| 67 | Moderate | 23 | |
| 52 | Moderate | 23 | |
| 52 | Moderate | 23 | |
| 63 | Moderate | 23 | |
| 60 | Moderate | 23 | |
| 55 | Moderate | 23 | |
| 52 | Moderate | 23 | |
| 53 | Moderate | 23 | |
| 71 | Moderate | 23 | |
| 79 | Moderate | 23 | |
| 61 | Moderate | 24 | |
| 64 | Moderate | 23 | |
| 58 | Moderate | 23 | |
| 73 | Moderate | 23 | |
| 112 | Unhealthy for Sensitive Groups | 23 | |
| 79 | Moderate | 23 | |
| 57 | Moderate | 22 | |
| 63 | Moderate | 23 | |
| 129 | Unhealthy for Sensitive Groups | 23 | |
| 87 | Moderate | 23 | |
| 104 | Unhealthy for Sensitive Groups | 24 | |
| 57 | Moderate | 23 | |
| 97 | Moderate | 23 | |
| 67 | Moderate | 23 | |
| 51 | Moderate | 24 | |
| 57 | Moderate | 23 | |
| 46 | Good | 23 | |
| 41 | Good | 26 | |
| 57 | Moderate | 7 — partial day |
Questions about Indianapolis
What is the air quality in Indianapolis right now?
Which monitor does this number come from?
How does Indianapolis compare with metros nearby?
Does this include pollen?
Put this number in context
Updated