PlainFlights

Route · IAD → SLC · 2020–2025 BTS data

Washington to Salt Lake City

According to PlainFlights' route traffic ranking (BTS On-Time Performance total flights), IAD to SLC (Washington to Salt Lake City) ranks #3886 of 4927 tracked domestic routes by total flights (most flights = #1).

Data updated 2026-06-13

86.9%
On-time
+7.9 pts
vs US avg
83 min
Delay when late
1,891
Flights
#3886 of 4927
Corpus placement

Cancelled

0.5%

Best Month

Aug 2025 94%

Worst Month

Jun 2025 64%

Distance

1,828 mi

Carriers

3

Monthly Performance

Recent 24 months of route data.

Period Flights Delayed Cancelled Diverted Carriers
Dec 2025 46 12 1 1 DL,UA
Nov 2025 59 15 0 0 UA,DL
Oct 2025 62 7 0 0 DL,UA
Sep 2025 60 8 0 0 UA,DL
Aug 2025 63 4 0 0 UA,DL
Jul 2025 62 8 0 0 DL,UA
Jun 2025 61 22 0 0 DL,UA
May 2025 62 7 1 1 DL,UA
Apr 2025 60 10 0 0 UA,DL
Mar 2025 62 7 0 0 DL,UA
Feb 2025 56 13 0 0 DL,UA
Jan 2025 62 15 1 1 DL,UA
Dec 2024 44 6 0 1 DL,UA
Nov 2024 30 4 0 0 DL
Oct 2024 31 2 0 0 DL
Sep 2024 30 0 0 0 DL
Aug 2024 31 5 0 0 DL
Jul 2024 31 6 2 0 DL
Jun 2024 30 0 0 0 DL
May 2024 31 1 0 0 DL
Apr 2024 30 3 0 0 DL
Mar 2024 31 1 0 0 DL
Jan 2024 31 4 0 0 DL
Dec 2023 31 3 0 0 DL

IAD–SLC seasonal on-time pattern

Best: September (93.3%) · weakest: February (76.8%)

75%80%85%90%95% JanFebMarAprMayJunJulAugSepOctNovDec 82.9%

Strongest calendar month

September

93.3% on-time · ~36 flights/mo

Busiest calendar month

February

~56 flights/mo avg

Weakest calendar month

February

76.8% on-time · ~56 flights/mo

Cancellation Rate

0.5%

5 of 1,096 flights

Diversion Rate

0.4%

4 of 1,096 flights

Origin-hub reliability standing

Among IAD's stronger departures

IAD → SLC posts a 86.9% on-time rate, landing in the ≥85% band with 14 of 58 BTS-tracked routes leaving Washington. The same hub also shows 42 mid-band and 2 challenged departures · fleet-wide on-time rank #649 of 4927 (highest on-time = #1).

What the Data Says About IAD to SLC

Washington to Salt Lake City (IAD to SLC) is one of the more dependable pairings in the BTS On-Time Performance dataset: a 86.9% on-time rate across 1,891 flights, with delays that do happen averaging 83.2 minutes. The corridor runs roughly 1,828 miles and is served by 3 carriers. Over the most recent 24 months, 5 of 1,096 flights were cancelled (0.5%) and 4 diverted (0.4%).

The monthly split is wide on this route: Aug 2025 posted the strongest performance at 94% on-time, while Jun 2025 came in at just 64% - a 30-point swing worth factoring into travel timing.

On the multi-year calendar, IAD–SLC peaks in September at 93.3% on-time while February carries the heaviest traffic (~56 flights per month) ; the softest month is February at 76.8%, a 16.5-point swing that repeats because the corridor's weather and holiday mix stays stable year to year.

Frequently Asked Questions

Where does IAD to SLC rank among US routes by traffic?
According to PlainFlights' route traffic ranking, IAD to SLC ranks #3886 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 IAD to SLC?
Flights from Washington to Salt Lake City have a 86.9% on-time rate based on 1,891 flights. The average delay is 83.2 minutes. The best recent month was Aug 2025 with 94% on-time.
What is the cancellation rate for IAD to SLC?
Over the last 24 months, 0.5% of flights on this route were cancelled (5 of 1,096 flights) and 0.4% were diverted.
How far is the flight from IAD to SLC?
The flight distance from Washington (IAD) to Salt Lake City (SLC) is approximately 1,828 miles. This route is served by 3 carriers.
When is the best time to fly from IAD to SLC?
The best recent month for on-time performance was Aug 2025 (94% on-time). The worst was Jun 2025 (64% on-time). Consider booking during months with historically better performance.

Airports on this route

Data source

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

Using IAD–SLC data

IAD–SLC runs 7.9 pts above the national 79% average; the remaining risk is month-to-month swing and carrier mix, not a weak headline rate.

  • Compare IAD and SLC airport profiles: delay causes and top routes differ even on the same corridor. IAD airport
  • If your dates flex, September (93.3% on-time) beats February (76.8%) on this corridor. Seasonal chart
  • 4 other routes post a similar 86.9% 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.