Flight Reliability
DL 815 · Delta Air Lines
Seattle → Nashville (SEA–BNA)89% of its flights flew this route. The rest (ATL–CHA) are included in these numbers.
87
Pretty Reliable
WanderNerd Reliability Score
- 83%
- Arrive within 15 minutes
- 2 min early
- Average arrival delay
- 0.9%
- Cancelled
- 10 min early
- Median arrival delay
Based on 325 historical flights. Data through May 2026.
What the data says
Friday is doing you no favors.
DL 815 arrived on time 87% of the time on Wednesdays. On Fridays: 75%.
A bit ahead of the SEA–BNA route.
DL 815 arrived on time 83% of the time, versus 77% across the SEA–BNA route.
Trending in the right direction.
DL 815 arrived on time 93% of the time over the last three months in the data, compared with 82% in the three months before that.
The breakdown
- Mon85%(48 flights)
- Tue79%(47 flights)
- Wed87%(47 flights)
- Thu87%(46 flights)
- Fri75%(47 flights)
- Sat83%(40 flights)
- Sun85%(47 flights)
- 3–6 PM83%(319 flights)
- 6–9 PM—(3 flights)
94%
May
Jun 80% → May 94% on time
| Month | On-time percentage | Flights |
|---|---|---|
| June 2025 | 80% | 30 |
| July 2025 | 74% | 31 |
| August 2025 | 85% | 27 |
| September 2025 | 64% | 22 |
| October 2025 | 71% | 31 |
| November 2025 | 93% | 29 |
| December 2025 | 81% | 31 |
| January 2026 | 84% | 25 |
| February 2026 | 82% | 11 |
| March 2026 | 88% | 24 |
| April 2026 | 97% | 30 |
| May 2026 | 94% | 31 |
- Departures on time
- 83%
- Diverted
- 0%
- Flights flown
- 322
- Months covered
- 12
Same route, other flights
Keep nerding
Based on 325 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.