Salt Lake City (SLC) to Washington (IAD): On-Time Performance
Data through July 2026
The calendar drives reliability on SLC–IAD. September 2024 flights landed on schedule 97% of the time, but July 2026 dropped to 63% — a gap of 34 points. Across the full period the route averages 84% on-time against a national 78%.
- On-time
- 84%
- arrived <15 min late
- Avg delay
- 11 min
- completed flights
- Cancelled
- 1.3%
- Flights/day
- 2.0
- last 12 months
- Duration
- 3h 59m
- scheduled
- Distance
- 1,827 mi
Best airline from SLC to IAD
2 airlines flew this route regularly between 2024-07 and 2026-07.
| Airline | On-time | Avg delay | Cancelled | Flights |
|---|---|---|---|---|
| United Airlinesmost reliable | 89% | 8 min | 1.6% | 572 |
| Delta Air Lines | 81% | 13 min | 1.1% | 761 |
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 (79%).
By day of week
| Day | On-time | Avg delay |
|---|---|---|
| Monday | 86% | 11 min |
| Tuesdaybest | 88% | 11 min |
| Wednesday | 84% | 9 min |
| Thursday | 80% | 15 min |
| Friday | 85% | 11 min |
| Saturday | 85% | 9 min |
| Sunday | 83% | 11 min |
What causes delays on this route
Share of total delay minutes by cause, as reported by carriers to the US DOT.
- Late-arriving aircraft20%
- Airline operations58%
- National airspace system18%
- Weather3%
Frequently asked questions
- How often are flights from SLC to IAD delayed?
- 16% of SLC–IAD flights arrived 15 or more minutes late (the US DOT definition of a delay) between 2024-07 and 2026-07. 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 89%, based on 572 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 (79%). 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 59m over 1,827 miles. Actual arrival times vary — flights on this route land 15+ minutes late 16% of the time.
- How often are SLC to IAD flights cancelled?
- 1.3% of scheduled flights on this route were cancelled between 2024-07 and 2026-07, at or below the national rate of 1.6%.
- What is the worst month to fly from SLC to IAD?
- July 2026 was the roughest month in this dataset, with only 63% of arrivals on time. The best was September 2024 at 97%. If your dates are flexible, that 34-point gap is worth planning around.
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Based on 1,333 flights, 2024-07–2026-07. Source: US DOT Bureau of Transportation Statistics. Updated 2026-09-28.