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Route · SLC → IAD · 2020–2025 BTS data

Salt Lake City to Washington

According to PlainFlights' route traffic ranking (BTS On-Time Performance total flights), SLC to IAD (Salt Lake City to Washington) ranks #3874 of 4927 tracked domestic routes by total flights (most flights = #1).

Data updated 2026-06-13

84.9%
On-time
+5.9 pts
vs US avg
82 min
Delay when late
1,920
Flights
#3874 of 4927
Corpus placement

Cancelled

0.6%

Best Month

Aug 2025 95%

Worst Month

Jul 2025 73%

Distance

1,828 mi

Carriers

3

Monthly Performance

Recent 24 months of route data.

Period Flights Delayed Cancelled Diverted Carriers
Dec 2025 46 6 1 0 DL,UA
Nov 2025 59 5 0 0 UA,DL
Oct 2025 62 7 0 0 UA,DL
Sep 2025 60 6 0 0 UA,DL
Aug 2025 62 3 0 0 UA,DL
Jul 2025 62 17 0 0 UA,DL
Jun 2025 61 15 0 0 UA,DL
May 2025 62 12 2 0 UA,DL
Apr 2025 59 7 1 0 DL,UA
Mar 2025 62 10 0 0 UA,DL
Feb 2025 56 12 0 0 UA,DL
Jan 2025 62 6 1 0 UA,DL
Dec 2024 44 10 0 0 DL,UA
Nov 2024 30 1 0 0 DL
Oct 2024 31 4 0 0 DL
Sep 2024 30 0 0 1 DL
Aug 2024 31 8 0 0 DL
Jul 2024 31 8 2 0 DL
Jun 2024 30 6 0 0 DL
May 2024 31 7 0 0 DL
Apr 2024 30 5 0 0 DL
Mar 2024 31 7 0 0 DL
Jan 2024 31 4 0 0 DL
Dec 2023 31 5 0 0 DL

SLC–IAD seasonal on-time pattern

Best: September (95.6%) · weakest: June (77.3%)

75%80%85%90%95%100% JanFebMarAprMayJunJulAugSepOctNovDec 83.6%

Strongest calendar month

September

95.6% on-time · ~36 flights/mo

Busiest calendar month

February

~56 flights/mo avg

Weakest calendar month

June

77.3% on-time · ~36 flights/mo

Cancellation Rate

0.6%

7 of 1,094 flights

Diversion Rate

0.1%

1 of 1,094 flights

Explore origin & destination

On-time and delay data for the airports this route connects.

SLC - Salt Lake City

Full on-time, delay-cause, and seasonal performance for Salt Lake City, UT.

SLC on-time profile

IAD - Washington

Full on-time, delay-cause, and seasonal performance for Washington, DC.

IAD on-time profile

Compare the two airports

See SLC and IAD side by side on delays, cancellations, and reliability.

Compare SLC vs IAD

Origin-hub reliability standing

Mid-pack among SLC departures

From SLC, this corridor sits with 31 other 75–85% on-time routes out of 85 tracked departures, not the hub's reliability leaders (54 at ≥85%) and not the softest ( 0 below 75%). Destination: Washington · fleet on-time rank #1277 of 4927.

What the Data Says About SLC to IAD

Bureau of Transportation Statistics records show Salt Lake City to Washington (SLC to IAD) running a 84.9% on-time rate over 1,920 tracked flights, on the stronger end of a typical domestic pairing. When flights do run late, the average delay is 81.7 minutes. The 1,828-mile corridor is served by 3 carriers, and over the last 24 months 0.6% of 1,094 flights were cancelled, 0.1% diverted.

The monthly split is wide on this route: Aug 2025 posted the strongest performance at 95% on-time, while Jul 2025 came in at just 73% - a 23-point swing worth factoring into travel timing.

On the multi-year calendar, SLC–IAD peaks in September at 95.6% on-time while February carries the heaviest traffic (~56 flights per month) ; the softest month is June at 77.3%, a 18.3-point swing that repeats because the corridor's weather and holiday mix stays stable year to year.

Frequently Asked Questions

Where does SLC to IAD rank among US routes by traffic? ▼
According to PlainFlights' route traffic ranking, SLC to IAD ranks #3874 of 4927 tracked domestic routes by total flights (most flights = #1). That ordinal matches our busiest-routes listing (total_flights DESC). See /methodology#corpus-placement for the exact sort basis.
How often are flights delayed from SLC to IAD? ▼
Flights from Salt Lake City to Washington have a 84.9% on-time rate based on 1,920 flights. The average delay is 81.7 minutes. The best recent month was Aug 2025 with 95% on-time.
What is the cancellation rate for SLC to IAD? ▼
Over the last 24 months, 0.6% of flights on this route were cancelled (7 of 1,094 flights) and 0.1% were diverted.
How far is the flight from SLC to IAD? ▼
The flight distance from Salt Lake City (SLC) to Washington (IAD) is approximately 1,828 miles. This route is served by 3 carriers.
When is the best time to fly from SLC to IAD? ▼
The best recent month for on-time performance was Aug 2025 (95% on-time). The worst was Jul 2025 (73% on-time). Consider booking during months with historically better performance.

Airports on this route

SLC Airport

Salt Lake City
IAD Airport

Washington
Data source

Data Source: Bureau of Transportation Statistics (BTS), On-Time Performance Data. Statistics reflect cumulative performance across all available reporting periods.

Read our methodology - how this data is sourced, computed, and verified.

Using SLC–IAD data

SLC–IAD runs 5.9 pts above the national 79% average; the remaining risk is month-to-month swing and carrier mix, not a weak headline rate.

  • Compare SLC and IAD airport profiles: delay causes and top routes differ even on the same corridor. SLC airport
  • If your dates flex, September (95.6% on-time) beats June (77.3%) on this corridor. Seasonal chart
  • 4 other routes post a similar 84.9% on-time rate; compare before you commit to this pairing. Similar routes

On-time rate reflects the BTS historical average across all reporting carriers on this origin–destination pair, not any single flight or booking recommendation.

Data sourced from U.S. Department of Transportation Bureau of Transportation Statistics (BTS) On-Time Performance data. See our methodology for details. Retrieved and formatted by PlainFlights

Every figure on PlainFlights is rendered directly from BTS On-Time Performance data, no number is typed in by an editor. This page aggregates this specific route's on-time performance and monthly trend, live from the dataset. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error.