Carrier route record

DLIDA→SLC

Delta Air Lines · Idaho Falls to Salt Lake City

Flights: 317
Period: July 2025 to June 2026
Share of route: 27%
Carriers: 2

Historical statistics for July 2025 to June 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 11 points better than the national rate of 77.6%. When something does go wrong the average delay runs about 2.8 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 11 points better than the US average of 77.6%. That gap is worth roughly 106 fewer late arrivals for every thousand flights.

On time

88.2%

Arrivals under 15 minutes late, of 314 completed flights

Avg delay

167 min

Across delayed arrivals only, not all flights

Cancelled

0.95%

National rate is 1.81%

Whole route

91.6%

Every carrier on IDA to SLC, 1,189 flights

These figures cover 317 flights between July 2025 and June 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.

Carrier by carrier

Delta against every carrier on IDA to SLC

Delta flew 317 of the 1,189 flights on IDA to SLC, about 27% of it. Its 88.2% on time is 3 points worse than the route as a whole, which runs 91.6%. Ranked by on-time rate it is last of two carriers on the route, where the range runs from SkyWest at 92.9% to Delta at 88.2%.

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	872	92.9%	69 min	0.11%	A+
Delta Air Lines (this page)thin sample	317	88.2%	167 min	0.95%	A+

Flight by flight

Delta flight numbers on IDA to SLC

DL 233506:0088.2% · 317 flights

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 88.2% is the reliable figure here.

Across the year

Delta on IDA to SLC through the year

Jul–Sep 202592 flights93.5%
Oct–Dec 202580 flights83.3%
Jan–Mar 202666 flights89.2%
Apr–Jun 202679 flights86.1%

Scale runs 75% to 100%. Rows with fewer than 30 flights show a dash.

Monthly volumes are too low here to break the year into twelve reliable readings. What the twelve-month total says is 88.2% 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 93.5% on time and its weakest Oct–Dec 2025 at 83.3%, a swing of 10 points on roughly 79 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, Sunday is the strongest day at 95.5% on time and Wednesday the weakest at 80.0%. 16 points is a smaller lever than departure hour, but it is free.

Delay causes

Why Delta runs late on this route

One category carries most of the weight here. Carrier accounts for 86% of the 6,170 delay minutes carriers reported, and the remaining four split what is left. The split is by minutes rather than by flights, so a few very long delays count for as much as many short ones.

Carrier
86%
Extreme weather
6%
Late-arriving aircraft
4%
National Airspace System
4%

The largest share of delay minutes, 86%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. Unlike weather, that is a management outcome, and it is the category where the gap between two carriers on the same schedule is genuinely earned. It accounts for 5,277 of the 6,170 delay minutes reported here. The split is drawn from 6,170 reported delay minutes.

Cancellations sit at 0.95% against a national 1.81%, which is ordinary. Diversions add another 0.00%.

Connections and stage length

What a delay here costs

5.4% of arrivals land an hour or more late, close to the national 8.1%. That is the figure that decides a connection, and it says a 60 to 75 minute layover is reasonable here while anything under 45 minutes is a bet. Most delays on this route last about 2.8 hours, which a normal layover absorbs.

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 78.0% on time across 317 flights, 10 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 10 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 88.2% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 314 completed flights over 12 months sit behind that.

Where to go next

Source: US DOT Bureau of Transportation Statistics, on-time performance data, July 2025 to June 2026. Last updated 15 September 2026; recomputed monthly. How this data is collected.

Key figures