Carrier route record

DLIDA→SLC

Delta Air Lines · Idaho Falls to Salt Lake City

Flights: 317
Period: September 2025 to August 2026
Share of route: 27%
Carriers: 2

Historical statistics for September 2025 to August 2026, not live status. For today’s flights, check with Delta Air Lines.

Delta on IDA to SLC earns an A. Close to nine flights in ten arrive inside the 15-minute window the DOT uses to define an on-time arrival, which puts it 13 points better than the national rate of 77.3%. When something does go wrong the average delay runs about 2.9 hours. That rests on 317 flights, with a median arrival 8 minutes early.

Set against the rest of the country, Delta's IDA to SLC record is 13 points better than the US average of 77.3%. That gap is worth roughly 125 fewer late arrivals for every thousand flights.

On time

89.8%

Arrivals under 15 minutes late, of 313 completed flights

Avg delay

175 min

Across delayed arrivals only, not all flights

Cancelled

1.26%

National rate is 1.89%

Whole route

91.8%

Every carrier on IDA to SLC, 1,195 flights

These figures cover 317 flights between September 2025 and August 2026. The median arrival is 8 minutes early, which is the part an average hides: most flights here are fine, and the on-time rate is decided by a tail of badly late ones. On-time means under 15 minutes late, the DOT's own threshold.

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Carrier by carrier

Delta against every carrier on IDA to SLC

Delta flew 317 of the 1,195 flights on IDA to SLC, about 27% of it. Its 89.8% on time is 2 points worse than the route as a whole, which runs 91.8%. Ranked by on-time rate it is last of two carriers on the route, where the range runs from SkyWest at 92.6% to Delta at 89.8%.

Only one carrier clears this site's 365-flight floor here, so there is no comparison to draw. The table below is the full picture.

On-time performance by carrier on IDA to SLC
Airline	Flights	On time	Avg delay	Cancelled	Grade
SkyWest Airlines	878	92.6%	77 min	0.11%	A+
Delta Air Lines (this page)thin sample	317	89.8%	175 min	1.26%	A

Flight by flight

Delta flight numbers on IDA to SLC

DL 233506:0089.8% · 317 flights

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Departure window

When Delta runs best on this route

Departure time is the single lever a traveller controls, and it moves the odds more than most people expect. Each bar below is the on-time rate for flights scheduled to leave inside that window, across 317 flights.

There are not enough flights in each departure window to split Delta's IDA to SLC record by time of day without the percentages moving on noise. The headline rate of 89.8% is the reliable figure here.

Across the year

Delta on IDA to SLC through the year

Jul–Sep 202530 flights100.0%
Oct–Dec 202580 flights83.3%
Jan–Mar 202666 flights89.2%
Apr–Jun 202679 flights86.1%
Jul–Sep 202662 flights98.4%

Scale runs 75% to 100%.

Monthly volumes are too low here to break the year into twelve reliable readings. What the twelve-month total says is 89.8% on time across 317 flights.

Delta on IDA to SLC did not run the same all year. Its best quarter was Jul–Sep 2025 at 100.0% on time and its weakest Oct–Dec 2025 at 83.3%, a swing of 17 points on roughly 63 flights a quarter. The twelve-month rate averages over that, so if you are flying in a weak quarter the quarter's own figure is the better guide.

Across the week, Tuesday is the strongest day at 95.6% on time and Wednesday the weakest at 82.2%, a spread of 13 points.

Arrival by arrival

How late Delta on IDA to SLC runs when it is late

Delta on IDA to SLC often beats the schedule: 87 of 313 completed flights, 28%, arrived 15 minutes or more early. The 32 late arrivals split 14 under half an hour, 4 between 30 and 60 minutes, and 14 an hour or more.

15+ min early87 flights27.8%
Within 15 min194 flights62.0%
15–29 min late14 flights4.5%
30–59 min late4 flights1.3%
1–2 hours late4 flights1.3%
2+ hours late10 flights3.2%

Scale runs 0% to 100%.

Share of 313 completed flights by arrival against schedule.

4 of 27 late departures made up the time and arrived on time, 15% of them. 9 flights left on time and still arrived late.

The worst days

Worst days for Delta on IDA to SLC

The latest arrival of the period was on 28 May 2026, 16 hours 26 minutes behind schedule; most of its delay minutes were filed as carrier-caused (crew, maintenance, fuelling, baggage). The same cause led on four of the five worst days.

The latest arrivals of Delta on IDA to SLC in the period
Date	Arrived late by	Largest filed cause
28 May 2026	16 hours 26 minutes	Carrier
20 February 2026	14 hours 5 minutes	Carrier
3 December 2025	14 hours 4 minutes	Carrier
19 December 2025	12 hours 42 minutes	Carrier
12 February 2026	5 hours 13 minutes	Extreme weather

Delay causes

Why Delta runs late on this route

Carrier accounts for 89% of the 5,589 delay minutes carriers reported here, and the remaining four split what is left.

Carrier
89%
Extreme weather
7%
National Airspace System
4%

The largest share of delay minutes, 89%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. It accounts for 4,967 of the 5,589 delay minutes reported here. The split is drawn from 5,589 reported delay minutes.

Cancellations sit at 1.26% against a national 1.89%, which is ordinary. Diversions add another 0.00%.

Connections and stage length

What a delay here costs

Badly late arrivals are rare here: only 4.5% land an hour or more behind schedule, against 8.3% nationally. Connections built on this flight are about as safe as US domestic connections get, though a cancelled flight still ignores every layover you give it.

At 189 miles this is a short hop, and stage length matters more than it looks. A flight this short spends under two hours in the air, which leaves almost nothing to claw back a late pushback with. Delay here is decided on the ground, in the turn, which is why the 5am–8am window matters as much as it does.

The return leg is a different operation and performs like one: it runs 81.4% on time across 317 flights, 8 points below this direction. Departure banks, aircraft rotations and the congestion at each end all differ, so scoring the two directions together would average away a real 8 points of difference.

One caution: this is a thin sample. 317 flights over twelve months is enough to clear this site's floor but not enough to pin the rate down tightly, and a single bad week moves it by more than a point. Treat the grade as a rough reading.

What to do with this

Booking Delta on IDA to SLC

Put together: treat all of this as provisional. 317 flights over twelve months is enough to clear this site's floor and not enough to be confident to better than a couple of points. The 89.8% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 313 completed flights over 12 months sit behind that.

Where to go next

Source: US DOT Bureau of Transportation Statistics, on-time performance data, September 2025 to August 2026. Last updated 22 October 2026; recomputed monthly. How this data is collected.

Key figures