Flight OddsWN4438 STL → BOS
Southwest Airlines · St. Louis, MO to Boston, MA · 39 flights observed, 2026-04-09 to 2026-06-01 · 1,047 mi
WN4438 covers more than one route in the data window — the stats below are for STL → BOS, the one it has flown most recently. The others are linked under “Other routes”.
On-time arrival
62%
Median delay
+9 min
90th percentile
+54 min
Cancellation rate
0%
How often is WN4438 on time?
Across 39 flights on STL → BOS from 2026-04-09 to 2026-06-01, WN4438 arrived within 15 minutes of schedule 62% of the time. The median arrival delay was +9 min, and the worst 10% of flights arrived +54 min or later. 0% of flights were cancelled.
Delay distribution
Arrival delay for completed flights (excludes cancellations and diversions).
| Arrival | Flights | Share |
|---|---|---|
| Early / on-time | 24 | 62% |
| 16-30 min | 5 | 13% |
| 31-60 min | 7 | 18% |
| 61-120 min | 3 | 8% |
| 2+ hrs | 0 | 0% |
Performance by month
| Month | Flights | On-time | Avg delay |
|---|---|---|---|
| 2026-04 | 16 | 56% | +16 min |
| 2026-05 | 22 | 64% | +15 min |
| 2026-06 | 1 | 100% | -4 min |
Performance by day of week
| Day | Flights | On-time |
|---|---|---|
| Mon | 8 | 63% |
| Tue | No data | — |
| Wed | No data | — |
| Thu | 8 | 63% |
| Fri | 8 | 63% |
| Sat | 8 | 63% |
| Sun | 7 | 57% |
Other routes
Related
Based on US Department of Transportation Bureau of Transportation Statistics on-time data. Loading live conditions and full charts…