Flight OddsDL4031 SEA → ONT
Delta Air Lines · Seattle, WA to Ontario, CA · 347 flights observed, 2025-07-01 to 2026-06-30 · 956 mi
DL4031 covers more than one route in the data window — the stats below are for SEA → ONT, the one it has flown most recently. The others are linked under “Other routes”.
On-time arrival
90%
Median delay
-9 min
90th percentile
+16 min
Cancellation rate
0%
How often is DL4031 on time?
Across 347 flights on SEA → ONT from 2025-07-01 to 2026-06-30, DL4031 arrived within 15 minutes of schedule 90% of the time. The median arrival delay was -9 min, and the worst 10% of flights arrived +16 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 | 311 | 90% |
| 16-30 min | 18 | 5% |
| 31-60 min | 13 | 4% |
| 61-120 min | 3 | 1% |
| 2+ hrs | 1 | 0% |
Performance by month
| Month | Flights | On-time | Avg delay |
|---|---|---|---|
| 2025-07 | 29 | 83% | -2 min |
| 2025-08 | 31 | 87% | -2 min |
| 2025-09 | 30 | 97% | -11 min |
| 2025-10 | 31 | 100% | -13 min |
| 2025-11 | 30 | 87% | -8 min |
| 2025-12 | 19 | 89% | -15 min |
| 2026-01 | 27 | 89% | -7 min |
| 2026-02 | 28 | 82% | +0 min |
| 2026-03 | 30 | 93% | -6 min |
| 2026-04 | 30 | 90% | 0 min |
| 2026-05 | 31 | 90% | -3 min |
| 2026-06 | 30 | 90% | -2 min |
Performance by day of week
| Day | Flights | On-time |
|---|---|---|
| Mon | 50 | 88% |
| Tue | 51 | 88% |
| Wed | 50 | 90% |
| Thu | 50 | 90% |
| Fri | 48 | 92% |
| Sat | 48 | 90% |
| Sun | 49 | 92% |
Other routes
Related
Based on US Department of Transportation Bureau of Transportation Statistics on-time data. Loading live conditions and full charts…