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DelayAtlas

Route reliability record

HLNSLC

Helena to Salt Lake City

Flights
725
Period
July 2025 to June 2026
Distance
402 mi
Carriers
1
A+GRADE

This route earns an A+. Nearly every flight arrives inside the 15-minute window the DOT uses to define an on-time arrival, which puts it 18 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 725 HLN to SLC flights, with a median arrival 12 minutes early.

Set against the rest of the country, this route's record is 18 points better than the US average of 77.6%. That gap is worth roughly 183 fewer late arrivals for every thousand flights.

Key figures

On time

95.9%

Arrivals under 15 minutes late, of 723 completed flights

Avg delay

72 min

Across delayed arrivals only, not all flights

Cancelled

0.28%

National rate is 1.81%

Best carrier

SkyWest

95.9% on time across 725 flights

These figures cover 725 flights between July 2025 and June 2026. The median arrival is 12 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 HLN to SLC

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 HLN to SLC
AirlineFlightsOn timeAvg delayCancelledGrade
SkyWest Airlines72595.9%72 min0.28%A+

Flight by flight

Flights on HLN to SLC

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 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 725 flights.

  • 5am–8am365 flights96.7%
  • 8am–11am
  • 11am–2pm360 flights95.0%
  • 2pm–5pm
  • 5pm–8pm
  • 8pm–5am

Scale runs 85% to 100%. Rows with fewer than 30 flights show a dash.

The 5am–8am window is the strongest at 96.7% on time. The full set of windows spans 2 points.

Across the year

When delays peak on this route

Twelve months, one bar each, drawn from the same 725 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 month98J95F97M93A100M93J97J95A98S94O93N97D
Darker means more delays. Figures are on-time percentages.May best, November worst

May is the best month on the calendar at 100.0% on time. Shoulder season thins the schedule and takes the summer weather with it, and the operation gets its margin back. March was the busiest month here, with 62 flights.

The day of the week is close to irrelevant here: 3 points separates the best day from the worst. Weekly demand peaks are not what drives the delays on this operation.

On-time rate by day of the week94.2Mon97.2Tue97.1Wed97.0Thu94.2Fri95.1Sat96.1Sun
Monday: 94.2 percent on time. Tuesday: 97.2 percent on time. Wednesday: 97.1 percent on time. Thursday: 97.0 percent on time. Friday: 94.2 percent on time. Saturday: 95.1 percent on time. Sunday: 96.1 percent on time

Delay causes

Why this route gets delayed

One category carries most of the weight here. Carrier accounts for 82% of the 2,152 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
    82%
  • Extreme weather
    14%
  • National Airspace System
    5%

Extreme weather accounts for 14% 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 2.2 times the usual weather exposure. The split is drawn from 2,152 reported delay minutes.

The largest share of delay minutes, 82%, 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 1,760 of the 2,152 delay minutes reported here.

Cancellations are rare at 0.28%, 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 1.7% 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 402 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 runs 96.4% on time across 725 flights, within half a point of this direction. The two legs are scored separately because they usually differ; on this city pair they happen not to.

One caution: this is a thin sample. 725 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.

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

What to do with this

Booking this route

Put together: treat all of this as provisional. 725 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 95.9% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 723 completed flights over 12 months sit behind that.

Common questions

HLN to SLC questions

How often is HLN to SLC delayed?

About one flight in 25 arrives at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 4.1% of the 725 flights in this analysis, against 22.4% nationally. Delayed flights are late by a little over an hour on average.

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

95.9% of flights arrive on time here against a national 77.6%, a difference of 18 points in its favour. That is worth a A+ on this site's grading scale.

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

The 5am–8am departure window is the strongest at 96.7% on time. The 11am–2pm window is the weakest at 95.0%, 2 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 November delays on HLN to SLC?

November is the weakest month at 93.0% on time, compared with 100.0% in May. Across the year that is 7 points between the best and worst months. The seasonal swing is modest enough that it should not decide when you travel.

Related

Where to go next

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

Embed HLN to SLC’s on-time badge on your site

Paste this into a web page. The badge shows the current on-time rate, cancellation rate and grade, and updates every month. Preview it, or build a badge for another route or airport.

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.