Airport month record
STLMAR
St. Louis Lambert International in March 2026
- Departures
- 5,400
- Month
- March 2026
- National, same month
- 75.7%
- Carriers
- 10
Historical statistics for March 2026, not live status or a forecast for this year’s March. For today’s conditions at STL, see live FAA status.
STL in March sits in the middle of the pack with a B. Close to three flights in four arrive on time by the DOT's definition, level with the national rate of 75.7%. The late ones land a little over an hour behind schedule. That rests on 5,400 flights, of which Delta Air Lines flew 384 at 88.6% on time.
Delta Air Lines is the most reliable of the three carriers covered here at 88.6% on time across 384 flights.
Key figures
On time
75.3%
Arrivals under 15 minutes late, of 5,254 completed departures
Avg delay
74 min
Across delayed arrivals only, not all flights
Cancelled
2.52%
Nationally in March: 2.90%
Whole year
78.0%
STL across all twelve months
These figures cover 5,400 departures from St. Louis Lambert International in March 2026. 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
March next to STL's other months
Against STL's own year, March ran 3 points worse than the twelve-month rate of 78.0%, which makes it number nine of twelve months, best first. Cancellations are where March stands out: 2.52% of scheduled departures were called off, 2.0 times the airport's rate across the year. Either side of it, February ran 84.9% on time and April 80.8%, so a trip moved by a few weeks would have landed in a better stretch.
| Month | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| July 2025 | 5,855 | 71.7% | 73 min | 1.57% | C |
| August 2025 | 5,539 | 79.7% | 71 min | 0.96% | B+ |
| September 2025 | 5,321 | 83.8% | 58 min | 0.34% | B+ |
| October 2025 | 5,611 | 78.5% | 60 min | 0.27% | B+ |
| November 2025 | 5,202 | 80.1% | 76 min | 1.46% | B |
| December 2025 | 5,359 | 74.0% | 75 min | 0.90% | C+ |
| January 2026 | 4,683 | 83.1% | 74 min | 3.46% | B− |
| February 2026 | 4,484 | 84.9% | 64 min | 1.32% | B |
| March 2026 (this page) | 5,400 | 75.3% | 74 min | 2.52% | B |
| April 2026 | 5,156 | 80.8% | 65 min | 0.80% | B+ |
| May 2026 | 5,375 | 77.5% | 74 min | 0.84% | B+ |
| June 2026 | 5,463 | 69.0% | 68 min | 1.17% | C |
Departure window
The best time of day to leave STL in March
Departure time matters more here than the choice of carrier. The gap between the best and worst window is 24 points, against 14 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.
- 5am–8am1,039 flights87.0%
- 8am–11am1,238 flights84.4%
- 11am–2pm670 flights75.4%
- 2pm–5pm881 flights69.0%
- 5pm–8pm1,033 flights64.4%
- 8pm–5am539 flights62.6%
Scale runs 55% to 90%. Rows with fewer than 30 flights show a dash.
The 8pm–5am window is where this operation falls apart: 62.6% on time, against 87.0% 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 8am–11am window is the busiest, with 1,238 flights scheduled in it.
Across the week, Tuesday is the strongest day at 80.8% on time and Saturday the weakest at 68.6%. 12 points is a smaller lever than departure hour, but it is free.
Carrier by carrier
Which airlines ran best at STL in March
The choice of carrier is not cosmetic here. Delta Air Lines arrives on time 88.6% of the time; Southwest Airlines manages 74.3%. Sample sizes sit next to every figure, because a two-point gap across 3,324 flights means less than a ten-point one.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| Southwest Airlines | 3,324 | 74.3% | 59 min | 1.59% | C |
| American Airlines | 531 | 79.9% | 128 min | 2.45% | B |
| Delta Air Lines | 384 | 88.6% | 124 min | 3.91% | A− |
| SkyWest Airlinesthin sample | 283 | 69.8% | 109 min | 6.36% | C− |
| Republic Airwaysthin sample | 279 | 75.3% | 82 min | 5.73% | B− |
| Envoy Airthin sample | 158 | 66.9% | 83 min | 4.43% | C− |
| Frontier Airlinesthin sample | 150 | 64.1% | 73 min | 3.33% | D− |
| United Airlinesthin sample | 146 | 75.0% | 64 min | 1.37% | B |
| PSA Airlinesthin sample | 92 | 71.8% | 131 min | 5.43% | C− |
| Alaska Airlinesthin sample | 53 | 88.2% | 56 min | 3.77% | A− |
Delta Air Lines cancels 3.9% of what it schedules here, the highest in the table. A cancelled flight never appears in an on-time rate, so read that column alongside the punctuality one rather than after it.
Route by route
Busiest routes out of STL in March
| Route | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| STL to DEN · Denverthin sample | 317 | 73.1% | 65 min | 0.32% | C+ |
| STL to ATL · Atlantathin sample | 283 | 78.5% | 68 min | 3.18% | B− |
| STL to ORD · Chicagothin sample | 271 | 65.5% | 122 min | 8.12% | C− |
| STL to MCO · Orlandothin sample | 269 | 71.6% | 52 min | 2.97% | C |
| STL to LGA · New Yorkthin sample | 254 | 63.5% | 89 min | 9.06% | D− |
| STL to PHX · Phoenixthin sample | 233 | 78.9% | 63 min | 0.43% | B+ |
| STL to LAS · Las Vegasthin sample | 208 | 83.5% | 57 min | 0.96% | B+ |
| STL to DCA · Washingtonthin sample | 200 | 68.3% | 97 min | 3.00% | C |
| STL to MSP · Minneapolisthin sample | 186 | 77.2% | 95 min | 3.23% | B− |
| STL to DFW · Dallas-Fort Worththin sample | 186 | 73.3% | 107 min | 2.69% | C |
| STL to DAL · Dallasthin sample | 167 | 75.8% | 50 min | 1.20% | B |
| STL to DTW · Detroitthin sample | 161 | 78.2% | 94 min | 3.11% | B− |
| STL to HOU · Houstonthin sample | 139 | 76.8% | 75 min | 0.00% | B+ |
| STL to MIA · Miamithin sample | 136 | 80.0% | 65 min | 4.41% | B− |
| STL to MDW · Chicagothin sample | 136 | 71.8% | 68 min | 3.68% | C− |
| STL to RSW · Fort Myersthin sample | 133 | 74.2% | 56 min | 0.75% | C+ |
| STL to CLT · Charlottethin sample | 128 | 84.1% | 109 min | 1.56% | B |
| STL to TPA · Tampathin sample | 125 | 80.8% | 57 min | 3.20% | B− |
| STL to BOS · Bostonthin sample | 118 | 62.1% | 62 min | 1.69% | D |
| STL to PHL · Philadelphiathin sample | 116 | 73.0% | 85 min | 0.86% | C+ |
| STL to BNA · Nashvillethin sample | 110 | 76.6% | 59 min | 2.73% | B |
| STL to BWI · Baltimorethin sample | 107 | 71.2% | 65 min | 1.87% | C |
| STL to EWR · Newarkthin sample | 89 | 85.2% | 64 min | 1.12% | A |
| STL to SLC · Salt Lake Citythin sample | 87 | 88.2% | 178 min | 2.30% | A |
| STL to MCI · Kansas Citythin sample | 87 | 80.2% | 77 min | 1.15% | B |
Delay causes
What held STL up in March
One category carries most of the weight here. Late-arriving aircraft accounts for 44% of the 96,000 delay minutes carriers reported, and the remaining four split what is left. The split is by minutes rather than by flights, so a few very long delays count for as much as many short ones.
- 44%Late-arriving aircraft
- 34%Carrier
- 19%National Airspace System
- 3%Extreme weather
- 0%Security
44% 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 96,000 reported delay minutes here, that single category outweighs weather by 15 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 95,617 reported delay minutes.
Cancellations run at 2.52%, against 2.90% nationally. That is about one flight in 40 cancelled outright. A cancelled flight is invisible in every on-time figure on this page, so the punctuality numbers above describe only the flights that actually operated.
For anyone connecting, the number to weigh is not the on-time rate but the tail behind it. 9.4% of arrivals land a full hour or more behind schedule, against 9.5% nationally. A 45-minute layover does not survive that, and no amount of walking quickly changes it. Ninety minutes is the honest minimum here, and two hours if the onward flight is on a separate ticket.
What to do with this
Flying from STL in March
For a March trip through STL: expect 75.3% on time and 2.52% cancelled, going by March 2026. The 5am–8am window was the strongest part of the day.
Related
Where to go next
- St. Louis Lambert International (STL), the whole year
- STL in July71.7%
- STL in August79.7%
- STL in September83.8%
- STL in October78.5%
- STL in November80.1%
- STL in December74.0%
- STL in January83.1%
- STL in February84.9%
- STL in April80.8%
- STL in May77.5%
- STL in June69.0%
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.