Airport month record
INDAUG
Indianapolis International in August 2025
- Departures
- 3,876
- Month
- August 2025
- National, same month
- 77.4%
- Carriers
- 12
Historical statistics for August 2025, not live status or a forecast for this year’s August. For today’s conditions at IND, see live FAA status.
IND in August lands a B, 4 points better than the national rate of 77.4%. About one flight in five arrives 15 minutes late or worse, and those flights are late by a little over an hour on average. That is a workable record, not a spotless one. That rests on 3,876 flights, of which Delta Air Lines flew 425 at 89.5% on time.
Delta Air Lines is the most reliable of the four carriers covered here at 89.5% on time across 425 flights.
Key figures
On time
81.4%
Arrivals under 15 minutes late, of 3,825 completed departures
Avg delay
78 min
Across delayed arrivals only, not all flights
Cancelled
1.11%
Nationally in August: 1.08%
Whole year
80.2%
IND across all twelve months
These figures cover 3,876 departures from Indianapolis International in August 2025. On time means an arrival less than 15 minutes after the scheduled gate time, the DOT's threshold, and the national comparison uses every US departure in the same month rather than the whole year.
Against the year
August next to IND's other months
Against IND's own year, August ran about a point better than the twelve-month rate of 80.2%, which makes it number seven of twelve months, best first. Cancellations were unusually low for IND in August, at 1.11% against 1.91% across the year. Either side of it, July ran 74.9% on time and September 85.1%, so this month sits in line with its neighbours.
| Month | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| July 2025 | 4,222 | 74.9% | 85 min | 3.01% | C− |
| August 2025 (this page) | 3,876 | 81.4% | 78 min | 1.11% | B |
| September 2025 | 3,742 | 85.1% | 68 min | 0.56% | A+ |
| October 2025 | 4,354 | 83.2% | 70 min | 0.57% | B+ |
| November 2025 | 3,904 | 83.1% | 77 min | 2.84% | B |
| December 2025 | 3,906 | 69.5% | 75 min | 1.59% | C |
| January 2026 | 3,690 | 79.7% | 78 min | 4.44% | B− |
| February 2026 | 3,457 | 83.3% | 61 min | 2.57% | B |
| March 2026 | 4,362 | 76.7% | 87 min | 2.57% | B |
| April 2026 | 4,290 | 83.0% | 65 min | 1.19% | B |
| May 2026 | 4,324 | 82.5% | 62 min | 0.88% | B+ |
| June 2026 | 4,249 | 79.9% | 76 min | 1.88% | B |
Departure window
The best time of day to leave IND in August
Departure time matters more here than the choice of carrier. The gap between the best and worst window is 30 points, against 17 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.
- 5am–8am1,105 flights92.5%
- 8am–11am598 flights87.7%
- 11am–2pm603 flights84.0%
- 2pm–5pm661 flights74.8%
- 5pm–8pm763 flights67.5%
- 8pm–5am146 flights62.1%
Scale runs 55% to 100%. Rows with fewer than 30 flights show a dash.
The 8pm–5am window is where this operation falls apart: 62.1% on time, against 92.5% for the 5am–8am slot. By evening the aircraft flying these rotations have absorbed a full day of small delays and there is no slack left to recover in. The 5am–8am window is the busiest, with 1,105 flights scheduled in it.
Across the week, Wednesday is the strongest day at 87.6% on time and Sunday the weakest at 76.6%. 11 points is a smaller lever than departure hour, but it is free.
Carrier by carrier
Which airlines ran best at IND in August
The choice of carrier is not cosmetic here. Delta Air Lines arrives on time 89.5% of the time; American Airlines manages 72.8%. Sample sizes sit next to every figure, because a two-point gap across 565 flights means less than a ten-point one.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| Republic Airways | 1,107 | 84.7% | 64 min | 1.08% | B |
| Southwest Airlines | 874 | 81.7% | 56 min | 0.11% | B+ |
| American Airlines | 565 | 72.8% | 103 min | 2.48% | C |
| Delta Air Lines | 425 | 89.5% | 70 min | 1.18% | A |
| United Airlinesthin sample | 261 | 76.3% | 106 min | 1.53% | B |
| Spirit Airlinesthin sample | 137 | 86.0% | 98 min | 0.00% | A+ |
| SkyWest Airlinesthin sample | 118 | 83.1% | 73 min | 0.00% | B+ |
| Allegiant Airthin sample | 102 | 75.5% | 51 min | 0.00% | B+ |
| Frontier Airlinesthin sample | 99 | 78.4% | 76 min | 2.02% | B |
| PSA Airlinesthin sample | 77 | 74.0% | 154 min | 5.19% | C− |
| Alaska Airlinesthin sample | 59 | 64.4% | 50 min | 0.00% | D+ |
| Envoy Airthin sample | 52 | 86.3% | 133 min | 1.92% | A |
The spread between Delta and American is 17 points, wide enough that it should decide the booking. On a hundred trips that is 17 more arrivals inside the on-time window.
Route by route
Busiest routes out of IND in August
| Route | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| IND to ORD · Chicago | 409 | 80.5% | 88 min | 1.96% | B |
| IND to ATL · Atlantathin sample | 294 | 89.6% | 85 min | 1.70% | A |
| IND to DEN · Denverthin sample | 242 | 79.1% | 74 min | 0.83% | B+ |
| IND to LGA · New Yorkthin sample | 210 | 90.4% | 54 min | 0.95% | A+ |
| IND to DFW · Dallas-Fort Worththin sample | 197 | 74.6% | 117 min | 3.05% | C− |
| IND to EWR · Newarkthin sample | 195 | 79.2% | 80 min | 1.03% | B |
| IND to BOS · Bostonthin sample | 172 | 78.7% | 48 min | 1.74% | B |
| IND to DCA · Washingtonthin sample | 171 | 78.6% | 84 min | 1.75% | B |
| IND to CLT · Charlottethin sample | 143 | 73.8% | 112 min | 1.40% | C |
| IND to MCO · Orlandothin sample | 142 | 72.9% | 72 min | 0.70% | C+ |
| IND to PHL · Philadelphiathin sample | 133 | 76.7% | 70 min | 3.01% | B− |
| IND to MSP · Minneapolisthin sample | 113 | 83.2% | 60 min | 0.00% | B+ |
| IND to PHX · Phoenixthin sample | 103 | 79.6% | 53 min | 0.00% | B+ |
| IND to LAS · Las Vegasthin sample | 99 | 87.9% | 66 min | 0.00% | A+ |
| IND to BWI · Baltimorethin sample | 98 | 85.6% | 50 min | 1.02% | A |
| IND to JFK · New Yorkthin sample | 94 | 87.2% | 108 min | 0.00% | A+ |
| IND to IAD · Washingtonthin sample | 93 | 86.8% | 48 min | 2.15% | A |
| IND to AUS · Austinthin sample | 80 | 81.2% | 50 min | 0.00% | B+ |
| IND to TPA · Tampathin sample | 75 | 77.0% | 59 min | 0.00% | B+ |
| IND to LAX · Los Angelesthin sample | 72 | 88.9% | 66 min | 0.00% | A+ |
| IND to FLL · Fort Lauderdalethin sample | 67 | 88.1% | 107 min | 0.00% | A+ |
| IND to MIA · Miamithin sample | 62 | 66.7% | 122 min | 1.61% | C |
| IND to IAH · Houstonthin sample | 62 | 82.0% | 134 min | 1.61% | B |
| IND to SEA · Seattlethin sample | 59 | 64.4% | 50 min | 0.00% | D+ |
| IND to DTW · Detroitthin sample | 57 | 84.2% | 81 min | 0.00% | B+ |
Delay causes
What held IND up in August
Carriers report a reason for every delay minute they cause, in five DOT categories. The split below is by minutes, not by number of flights, so a handful of very long weather delays weighs as much as many short ones. It covers 56,000 reported delay minutes.
- 41%Late-arriving aircraft
- 27%National Airspace System
- 26%Carrier
- 6%Extreme weather
- 0%Security
41% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. That is a cascade, and cascades start small and grow through the day. Across 56,000 reported delay minutes here, that single category outweighs weather by 7 to one. It is the strongest argument for booking the first departure of the morning, when the aircraft has been sitting at the gate overnight with nothing to inherit. The split is drawn from 55,519 reported delay minutes.
Cancellations sit at 1.11% against a national 1.08%, which is ordinary. Diversions add another 0.21%.
6.5% of arrivals land an hour or more late, close to the national 8.2%. That is the figure that decides a connection, and it says a 60 to 75 minute layover is reasonable here while anything under 45 minutes is a bet. Most delays on this route last a little over an hour, which a normal layover absorbs.
What to do with this
Flying from IND in August
For a August trip through IND: expect 81.4% on time and 1.11% cancelled, going by August 2025. The 5am–8am window was the strongest part of the day.
Related
Where to go next
- Indianapolis International (IND), the whole year
- IND in July74.9%
- IND in September85.1%
- IND in October83.2%
- IND in November83.1%
- IND in December69.5%
- IND in January79.7%
- IND in February83.3%
- IND in March76.7%
- IND in April83.0%
- IND in May82.5%
- IND in June79.9%
Source: US DOT Bureau of Transportation Statistics, on-time performance data, July 2025 to June 2026. Last updated 15 September 2026; recomputed monthly. How this data is collected.