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DelayAtlas

Route reliability record

SLCIDA

Salt Lake City to Idaho Falls

Flights
1,189
Period
July 2025 to June 2026
Distance
189 mi
Carriers
2
A+GRADE

This route 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 12 points better than the national rate of 77.6%. When something does go wrong the average delay runs a little over an hour. That rests on 1,189 SLC to IDA flights, with a median arrival 8 minutes early.

Best time to fly SLC to IDA: a 8am–11am departure, ideally on a Saturday. Flights in that window arrived on time 98.3% of the time and Saturday flights 93.1%, against 89.3% for the route overall.

Set against the rest of the country, this route's record is 12 points better than the US average of 77.6%. That gap is worth roughly 117 fewer late arrivals for every thousand flights.

Key figures

On time

89.3%

Arrivals under 15 minutes late, of 1,183 completed flights

Avg delay

72 min

Across delayed arrivals only, not all flights

Cancelled

0.34%

National rate is 1.81%

Best carrier

SkyWest

93.3% on time across 872 flights

These figures cover 1,189 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

Which airline is most reliable on SLC to IDA

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 SLC to IDA
AirlineFlightsOn timeAvg delayCancelledGrade
SkyWest Airlines87293.3%76 min0.11%A+
Delta Air Linesthin sample31778.0%69 min0.95%B+

Flight by flight

Flights on SLC to IDA

The flight numbers below flew this route at least 250 times in the period, busiest first. Each has its own record, with its schedule and delay causes.

Departure window

The best time of day to leave

Departure time matters more here than the choice of carrier. The gap between the best and worst window is 22 points, against half a point between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.

  • 5am–8am2 flights
  • 8am–11am117 flights98.3%
  • 11am–2pm365 flights94.5%
  • 2pm–5pm47 flights76.6%
  • 5pm–8pm294 flights91.5%
  • 8pm–5am364 flights80.8%

Scale runs 70% to 100%. Rows with fewer than 30 flights show a dash.

Book the morning departure. Flights leaving between 8am–11am arrive on time 98.3% of the time, against 76.6% for the afternoon window. That is 22 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 11am–2pm window is the busiest, with 365 flights scheduled in it.

Across the year

When delays peak on this route

Twelve months, one bar each, drawn from the same 1,189 flights. The strip shows how much of this route's record is set by the calendar rather than by the operation.

On-time rate by calendar month84J84F91M90A90M96J87J87A91S89O93N86D
Darker means more delays. Figures are on-time percentages.June best, February worst

February is the weak month at 84.2% on time, against 95.8% in June. Winter delays cluster: a single storm system can account for most of a month's shortfall, so an average December hides both very good weeks and genuinely unflyable days. August was the busiest month here, with 122 flights.

Across the week, Saturday is the strongest day at 93.1% on time and Sunday the weakest at 84.6%. 9 points is a smaller lever than departure hour, but it is free.

On-time rate by day of the week89.5Mon91.4Tue89.8Wed88.2Thu88.4Fri93.1Sat84.6Sun
Monday: 89.5 percent on time. Tuesday: 91.4 percent on time. Wednesday: 89.8 percent on time. Thursday: 88.2 percent on time. Friday: 88.4 percent on time. Saturday: 93.1 percent on time. Sunday: 84.6 percent on time

Delay causes

Why this route gets delayed

One category carries most of the weight here. Carrier accounts for 64% of the 9,138 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
    64%
  • Extreme weather
    18%
  • Late-arriving aircraft
    11%
  • National Airspace System
    8%

Extreme weather accounts for 18% of delay minutes, well above the single-digit share typical across the system. Weather delays are lumpy: they arrive as whole bad days rather than as a steady drag, so the monthly strip above is the more useful view of the risk. The national share is 6%, so this operation carries roughly 2.9 times the usual weather exposure. The split is drawn from 9,138 reported delay minutes.

The largest share of delay minutes, 64%, 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 5,813 of the 9,138 delay minutes reported here.

Cancellations are rare at 0.34%, below the national 1.81% and low enough to earn the plus on the grade. Roughly one flight in 100 is called off; the risk here is arriving late, not not arriving.

Connections and stage length

What a delay here actually costs

Badly late arrivals are rare here: only 4.6% land an hour or more behind schedule, against 8.1% 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 8am–11am window matters as much as it does.

The return leg runs 91.6% on time across 1,189 flights, within 2 points of this direction. The two legs are scored separately because they usually differ; on this city pair they happen not to.

The sample behind these figures is 1,189 flights, enough that the headline rate is stable to within roughly a point. The hour-block and month splits divide that further, so read the thinner bars with more caution than the headline.

Work out the risk of missing a connection in IDA after this flight

What to do with this

Booking this route

Put together: take the 8am–11am departure, avoid February if the dates are flexible, and if two carriers are within a few dollars of each other, SkyWest is the one with the record behind it. None of that guarantees an on-time arrival; it moves the odds by 22 points, which is the most any booking decision can do. 1,183 completed flights over 12 months sit behind that.

Common questions

SLC to IDA questions

How often is SLC to IDA delayed?

About one flight in nine arrives at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 10.7% of the 1,189 flights in this analysis, against 22.4% nationally. Delayed flights are late by a little over an hour on average.

How reliable is SLC to IDA compared with the rest of the country?

89.3% of flights arrive on time here against a national 77.6%, a difference of 12 points in its favour. That is worth a A+ on this site's grading scale.

What time of day has the fewest delays on SLC to IDA?

The 8am–11am departure window is the strongest at 98.3% on time. The 2pm–5pm window is the weakest at 76.6%, 22 points behind. Later departures inherit delays from earlier flights the same aircraft has already flown, which is why the curve slopes the way it does.

How bad are February delays on SLC to IDA?

February is the weakest month at 84.2% on time, compared with 95.8% in June. Across the year that is 12 points between the best and worst months. Moving flexible dates out of that month is one of the few things that reliably helps.

Related

Where to go next

Direction matters. SLC to IDA and IDA to SLC are scored separately because they are separate operations, with different departure banks and different aircraft. Compare the return leg.

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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.