The Most (and Least) Reliable US Flight Routes

The most reliable flight route in the US is Sun Valley to Salt Lake City (SUN → SLC), on time 94.4% of the time. The least reliable route with meaningful volume is Jackson Hole to Dallas/Fort Worth (JAC → DFW), on time just 68.0% of the time with a 53.1-minute average arrival delay. These figures come from 14.1 million US flights between June 2024 and May 2026, reported to the US DOT.

• SUN → SLC — 94.4% on-time, the most reliable route in the country with real traffic, flown by SkyWest as a regional connection into Salt Lake City.
• JAC → DFW — 68.0% on-time, the least reliable busy route, with a 53.1-minute average arrival delay when it runs late.
• ORD ↔ LGA — the busiest city pair in the data, roughly 11,600 flights a year each direction, yet only about 72% on-time.
• SkyWest's Salt Lake City network — four of the five most reliable routes in the country connect through Salt Lake City on SkyWest's regional network, not a mainline carrier's own aircraft.

How we ranked the routes

These rankings use the same US DOT Bureau of Transportation Statistics data as the rest of FlightRecord — 14.1 million flights over 24 months, from June 2024 through May 2026. To keep the comparisons meaningful, the most reliable list only includes routes flying at least 1,000 times a year, and the most delayed list only includes routes flying at least 500 times a year, enough volume that one bad week can't swing the average. A flight counts as on time if it arrives within 15 minutes of its scheduled time — see what counts as a delayed flight for the full definition.

The most reliable US flight routes

The five most reliable routes with real traffic all connect through Salt Lake City International (SLC), and all five are flown by SkyWest Airlines' regional network rather than a mainline carrier's own metal. Sun Valley, Idaho (SUN) to Salt Lake City tops the list at 94.4% on-time, with Tucson (TUS) to Salt Lake City close behind at 94.3%.

• SUN → SLC — 94.4% on-time, the single most reliable route with at least 1,000 flights a year.
• TUS → SLC — 94.3% on-time.
• SLC → SUN — 93.8% on-time — the return leg holds up almost as well as the outbound.
• SLC → GTF — 93.5% on-time, connecting Salt Lake City to Great Falls, Montana.
• ABQ → SLC — 93.1% on-time, from Albuquerque.

See every route that qualifies on the most reliable routes ranking.

The least reliable US flight routes (most delayed)

On the other end, the least reliable routes with meaningful volume — at least 500 flights a year — run far behind the 78.2% national average. Jackson Hole, Wyoming (JAC) to Dallas/Fort Worth (DFW) is the worst of the group: only 68.0% of flights arrive on time, and when a flight does run late, it averages 53.1 minutes behind schedule.

• JAC → DFW — 68.0% on-time, 53.1 min average arrival delay.
• IAH → VCT — 77.1% on-time, 41.5 min average delay, connecting Houston to Victoria, Texas.
• AUS → PHL — 74.3% on-time, 40.2 min average delay, from Austin to Philadelphia.
• ASE → ORD — 62.0% on-time, 39.3 min average delay, the lowest on-time rate on this list, from Aspen to Chicago O'Hare.
• ORD → CMX — 67.4% on-time, 39.0 min average delay, connecting O'Hare to Hancock/Houghton, Michigan.

Four of these five routes touch a small, often weather-exposed airport on one end — Jackson Hole, Aspen, Victoria, or Michigan's Upper Peninsula — and a major connecting hub on the other. That combination compounds: mountain weather or a thin schedule at the small airport creates the initial delay, and hub congestion at the other end keeps it from being absorbed.

The busiest US routes — and how reliable they are

The busiest routes in the country don't line up with the most reliable ones. Chicago O'Hare and New York LaGuardia are connected by the highest-volume city pair in FlightRecord's data, with roughly 11,600 flights each direction over the past year — but only about 72% of them arrive on time, well below the 78.2% national average.

• ORD → LGA — about 11,634 flights a year, 71.3% on-time.
• LGA → ORD — about 11,633 flights a year, 72.6% on-time.
• SFO → LAX — about 10,834 flights a year, 78.6% on-time.
• LAX → SFO — about 10,832 flights a year, 72.1% on-time — the same city pair, a very different result depending on direction.
• JFK → LAX — 10,337 flights a year, 80.3% on-time, the most reliable of the country's busiest routes.

See the complete list on the busiest routes ranking, or check the best airline by route ranking to see which carrier handles each of these high-traffic pairs best.

Why do short regional routes outperform the big hubs?

Three patterns explain most of the gap between the most and least reliable routes in this data.

Distance and congestion work against the busiest routes. ORD↔LGA and SFO↔LAX are flown by mainline aircraft into two of the most congested airport systems in the country — Chicago O'Hare and the New York airports both carry heavy connecting traffic, and Los Angeles and San Francisco share some of the tightest airspace on the West Coast. A route can be flown thousands of times a year and still inherit its endpoints' congestion.

Short regional hops recover faster. SUN→SLC, TUS→SLC, and the other Salt Lake City routes at the top of the list are short flights connecting a small origin airport to a single hub, flown by SkyWest's regional network. That matches a broader pattern in FlightRecord's data: regional partner carriers often outperform the majors' own mainline metal, as detailed in which US airlines have the best (and worst) on-time records. Shorter flights also leave less time in the air for weather or air-traffic-control delays to build.

Small regional airports drag down the delayed list for a related but opposite reason. Jackson Hole, Aspen, and Victoria are exactly the kind of small, often weather-exposed airports where a single bad-weather day at the origin can ripple through the rest of that aircraft's schedule — the same mechanism behind late-arriving aircraft delays site-wide.

How to check a specific route before you book

Route-level averages are still a starting point — the same route can run close to perfect on one airline and struggle on another serving the identical city pair. Before booking, look up your specific route on FlightRecord and see which carrier the data favors on that pair, or check that flight's own on-time history if you already have a flight number rather than relying on the route average alone. For the full picture on how every figure on this site is calculated, see FlightRecord's methodology.

Route reliability can also depend heavily on which airline you book — see same route, different airline: how much does on-time performance really vary.

Frequently asked questions

What is the most reliable flight route in the US?

Sun Valley, Idaho to Salt Lake City (SUN → SLC) is the most reliable US route with meaningful volume, arriving on time 94.4% of the time. It's one of five SkyWest-operated regional routes connecting to Salt Lake City that dominate the top of the list.

What is the least reliable flight route in the US?

Among routes with at least 500 flights a year, Jackson Hole to Dallas/Fort Worth (JAC → DFW) has the lowest on-time rate, at 68.0%, with an average arrival delay of 53.1 minutes when it runs late.

What is the busiest flight route in the US?

Chicago O'Hare to New York LaGuardia (ORD ↔ LGA) is the highest-volume route in FlightRecord's data, with roughly 11,600 flights a year in each direction — though only about 72% of them arrive on time.

Why are short regional routes more reliable than routes between major hubs?

Short regional routes typically connect a small origin airport to a single hub on one aircraft type, leaving less time in the air for delays to build and fewer downstream flights to disrupt if something goes wrong. Routes between two major hubs inherit congestion from both endpoints, which drags down on-time performance even at high volume.

What time period does this route data cover?

These figures come from 14.1 million US flights between June 2024 and May 2026, reported to the US Department of Transportation's Bureau of Transportation Statistics. The most reliable ranking includes routes flying at least 1,000 times a year; the most delayed ranking includes routes flying at least 500 times a year.