Flight Reliability
DL 1120 · Delta Air Lines
Seattle → Salt Lake City (SEA–SLC)
89
Pretty Reliable
WanderNerd Reliability Score
- 84%
- Arrive within 15 minutes
- 2 min
- Average arrival delay
- 0.5%
- Cancelled
- 8 min early
- Median arrival delay
Based on 365 historical flights. Data through May 2026.
What the data says
Skip Thursday if you can.
DL 1120 arrived on time 89% of the time on Wednesdays. On Thursdays: 77%.
Trending in the right direction.
DL 1120 arrived on time 89% of the time over the last three months in the data, compared with 78% in the three months before that.
The breakdown
- Mon83%(52 flights)
- Tue88%(51 flights)
- Wed89%(52 flights)
- Thu77%(52 flights)
- Fri80%(51 flights)
- Sat84%(51 flights)
- Sun85%(53 flights)
87%
May
Jun 93% → May 87% on time
| Month | On-time percentage | Flights |
|---|---|---|
| June 2025 | 93% | 30 |
| July 2025 | 62% | 29 |
| August 2025 | 77% | 31 |
| September 2025 | 93% | 30 |
| October 2025 | 84% | 31 |
| November 2025 | 93% | 30 |
| December 2025 | 71% | 31 |
| January 2026 | 74% | 31 |
| February 2026 | 89% | 28 |
| March 2026 | 87% | 30 |
| April 2026 | 93% | 30 |
| May 2026 | 87% | 31 |
- Departures on time
- 81%
- Diverted
- 0.3%
- Flights flown
- 362
- Months covered
- 12
Same route, other flights
Keep nerding
Based on 365 historical flights, because apparently we checked. Historical flight data: U.S. Bureau of Transportation Statistics, June 2025 – May 2026. Data through May 2026. How we calculate this.