Flight Reliability
DL 629 · Delta Air Lines
Atlanta → Seattle (ATL–SEA)
87
Pretty Reliable
WanderNerd Reliability Score
- 81%
- Arrive within 15 minutes
- 1 min
- Average arrival delay
- 0.3%
- Cancelled
- 5 min early
- Median arrival delay
Based on 365 historical flights. Data through May 2026.
What the data says
Saturday is the weak spot.
DL 629 arrived on time 89% of the time on Sundays. On Saturdays: 75%.
A bit ahead of the ATL–SEA route.
DL 629 arrived on time 81% of the time, versus 78% across the ATL–SEA route.
It basically never cancels.
Out of 365 scheduled flights, only 0.3% were cancelled.
Trending in the right direction.
DL 629 arrived on time 85% of the time over the last three months in the data, compared with 63% in the three months before that.
The breakdown
- Mon79%(52 flights)
- Tue79%(52 flights)
- Wed87%(52 flights)
- Thu79%(52 flights)
- Fri82%(51 flights)
- Sat75%(51 flights)
- Sun89%(53 flights)
- 9 AM–12 PM82%(146 flights)
- 12–3 PM81%(217 flights)
84%
May
Jun 77% → May 84% on time
| Month | On-time percentage | Flights |
|---|---|---|
| June 2025 | 77% | 30 |
| July 2025 | 90% | 31 |
| August 2025 | 87% | 31 |
| September 2025 | 93% | 30 |
| October 2025 | 90% | 31 |
| November 2025 | 93% | 30 |
| December 2025 | 48% | 31 |
| January 2026 | 73% | 30 |
| February 2026 | 68% | 28 |
| March 2026 | 83% | 30 |
| April 2026 | 87% | 30 |
| May 2026 | 84% | 31 |
- Departures on time
- 82%
- Diverted
- 0.3%
- Flights flown
- 363
- 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.