Flight OddsDL4031 ONT → SEA
Delta Air Lines · Ontario, CA to Seattle, WA · 321 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 ONT → SEA, the one it has flown most recently. The others are linked under “Other routes”.
On-time arrival
90%
Median delay
-11 min
90th percentile
+16 min
Cancellation rate
0%
How often is DL4031 on time?
Across 321 flights on ONT → SEA from 2025-07-01 to 2026-06-30, DL4031 arrived within 15 minutes of schedule 90% of the time. The median arrival delay was -11 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 | 287 | 90% |
| 16-30 min | 17 | 5% |
| 31-60 min | 10 | 3% |
| 61-120 min | 1 | 0% |
| 2+ hrs | 5 | 2% |
Performance by month
| Month | Flights | On-time | Avg delay |
|---|---|---|---|
| 2025-07 | 29 | 90% | -3 min |
| 2025-08 | 31 | 87% | -1 min |
| 2025-09 | 30 | 90% | -5 min |
| 2025-10 | 31 | 90% | -3 min |
| 2025-11 | 28 | 89% | -4 min |
| 2025-12 | 19 | 89% | -2 min |
| 2026-01 | 27 | 96% | -5 min |
| 2026-02 | 11 | 91% | -22 min |
| 2026-03 | 23 | 91% | -10 min |
| 2026-04 | 30 | 87% | -7 min |
| 2026-05 | 31 | 87% | -8 min |
| 2026-06 | 30 | 90% | -5 min |
Performance by day of week
| Day | Flights | On-time |
|---|---|---|
| Mon | 47 | 94% |
| Tue | 48 | 85% |
| Wed | 47 | 91% |
| Thu | 45 | 89% |
| Fri | 43 | 86% |
| Sat | 44 | 93% |
| Sun | 46 | 89% |
Other routes
Related
Based on US Department of Transportation Bureau of Transportation Statistics on-time data. Loading live conditions and full charts…