Salt Lake City (SLC) to Washington (IAD): On-Time Performance
Data through May 2026
The calendar drives reliability on SLC–IAD. September 2024 flights landed on schedule 97% of the time, but July 2024 dropped to 72% — a gap of 24 points. Across the full period the route averages 85% on-time against a national 78%.
- On-time
- 85%
- arrived <15 min late
- Avg delay
- 11 min
- completed flights
- Cancelled
- 1.1%
- Flights/day
- 2.0
- last 12 months
- Duration
- 3h 58m
- scheduled
- Distance
- 1,827 mi
Best airline from SLC to IAD
2 airlines flew this route regularly between 2024-06 and 2026-05.
| Airline | On-time | Avg delay | Cancelled | Flights |
|---|---|---|---|---|
| United Airlinesmost reliable | 88% | 8 min | 1.2% | 512 |
| Delta Air Lines | 83% | 13 min | 1.1% | 730 |
Monthly on-time trend
Best time to fly from SLC to IAD
Aim for departures around 8 a.m. (97% on-time); avoid 1 p.m. departures (80%).
By day of week
| Day | On-time | Avg delay |
|---|---|---|
| Monday | 86% | 12 min |
| Tuesdaybest | 89% | 11 min |
| Wednesday | 84% | 9 min |
| Thursday | 82% | 12 min |
| Friday | 85% | 12 min |
| Saturday | 86% | 9 min |
| Sunday | 83% | 12 min |
What causes delays on this route
Share of total delay minutes by cause, as reported by carriers to the US DOT.
- Late-arriving aircraft21%
- Airline operations60%
- National airspace system17%
- Weather3%
Frequently asked questions
- How often are flights from SLC to IAD delayed?
- 15% of SLC–IAD flights arrived 15 or more minutes late (the US DOT definition of a delay) between 2024-06 and 2026-05. The average arrival delay across completed flights was 11 minutes.
- Which airline is most reliable from SLC to IAD?
- United Airlines has the best on-time record on this route at 88%, based on 512 flights. 2 airlines flew SLC–IAD frequently enough to compare in this period.
- What is the best time of day to fly from SLC to IAD?
- Departures around 8 a.m. have the best record (97% on-time), while departures around 1 p.m. have the worst (80%). As on most US routes, delays accumulate through the day, so earlier flights are generally safer.
- How long is the flight from SLC to IAD?
- The scheduled SLC–IAD flight time averages 3h 58m over 1,827 miles. Actual arrival times vary — flights on this route land 15+ minutes late 15% of the time.
- How often are SLC to IAD flights cancelled?
- 1.1% of scheduled flights on this route were cancelled between 2024-06 and 2026-05, at or below the national rate of 1.6%.
- What is the worst month to fly from SLC to IAD?
- July 2024 was the roughest month in this dataset, with only 72% of arrivals on time. The best was September 2024 at 97%. If your dates are flexible, that 24-point gap is worth planning around.
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Based on 1,242 flights, 2024-06–2026-05. Source: US DOT Bureau of Transportation Statistics. Updated 2026-07-01.