81% of flights leaving Idaho Falls (IDA) arrived on time over the past 12 months, 5 points better than the national average of 76%. About 14 flights leave IDA on a typical day; 0.6% were cancelled. 82% pushed back from the gate on time, so most of the lateness is already there when the flight leaves the gate.
At a glance
- Best hour to fly: 6 a.m. (89% on time). Worst: 4 p.m. (65%).
- Best month: November (86%). Worst: July (77%).
- Most reliable airline here: Delta Air Lines (91%), vs United Airlines at 80%.
- Biggest delay cause: the airlines themselves (50% of delay minutes).
- Year on year: improving (79% → 81%).
How late?
The on-time rate treats a flight 20 minutes late the same as one 5 hours late. Here's the split for flights leaving IDA: when a flight was late, it was under 45 minutes late 49% of the time. About 1 in 13 flights landed an hour or more late, and 1 in 45 three hours or more; 0.6% were cancelled outright.
- On time or early81%
- 15–30 min late5.9%
- 30–60 min late4.8%
- 1–2 hours late3.6%
- 2–3 hours late1.7%
- 3+ hours late2.2%
- Diverted0.5%
- Cancelled0.6%
Share of all 5,105 scheduled flights, past 12 months, by arrival time against schedule.
Best time of day to fly out of IDA
Time of day matters more at IDA than almost anything else you control. Flights scheduled to leave at 6 a.m. arrived on time 89% of the time; at 4 p.m. it was 65%, a 24-point gap. Taken together, early departures (5–9 a.m.) ran 89% on time against 79% for the evening bank (5–10 p.m.). Early planes usually start the day at the airport, so they haven't had a chance to pick up delays elsewhere. By evening a late inbound aircraft, a crew running out of duty hours or an afternoon thunderstorm can push one late flight into the next. Cancellations cluster too: 1 p.m. departures were cancelled 1.0% of the time, against 0.6% overall.
Hour × month
Combine the two and the spread is wider still. The most reliable combination at IDA was a 6 a.m. departure in August (96% on time); the least, 4 p.m. in August (48%). If you can only move one thing, move the hour. Departure hour usually shifts the odds more than the month does.
Each cell: on-time rate for that departure hour in that calendar month, 2023–2026. Find your travel month, then look along the row for the greenest hour.
Best and worst months
July is the hardest month at IDA, with 77% of flights on time across 2023–2026; November is the best at 86%. Summer (June–August) runs 6 points worse than autumn: heavy schedules, peak loads and afternoon thunderstorms. Winter costs 4 points against autumn. Cancellations peak in January (1.4% of flights).
Airlines at IDA
United Airlines runs 33% of departures from IDA. Among airlines with at least 1,000 departures here, Delta Air Lines was the most reliable (91% on time) and United Airlines the least (80%), a 12-point difference. On a route where both fly, that difference is worth more than a small fare gap.
| Airline | Departures | On time | Left on time | Cancelled | Typical arrival |
|---|---|---|---|---|---|
| United Airlines | 1,680 | 80% | 81% | 0.4% | −11 min |
| Delta Air Lines | 1,195 | 91% | 92% | 0.4% | −11 min |
| American Airlines | 920 | 73% | 75% | 1.5% | −9 min |
| Alaska Airlines | 832 | 81% | 85% | 0.4% | −4 min |
| Allegiant Air | 478 | 70% | 70% | 0.4% | −1 min |
Why flights are late at IDA
Airlines report a cause for every flight that arrives 15 or more minutes late. At IDA, 50% of delay minutes came from the airlines themselves: crew, maintenance, cleaning, fueling and baggage. Next is late-arriving aircraft at 25%.
The average taxi from gate to takeoff is 19 minutes, longer than at most large U.S. airports. Airlines pad schedules for it, but a long queue on a busy afternoon still eats into the buffer.
Month by month
Over the latest 12 months 81% of IDA departures were on time, against 79% in the 12 months before, an improvement of 2 points. The best recent month was November 2025 (87%); the worst, August 2026 (75%).
Worst cancellation days
The worst single day in the past year was Saturday, Mar 7, 2026, when 18% of 11 scheduled departures were cancelled. Days like that are usually a major storm, a system outage or a holiday peak hitting bad weather. No average predicts them, so on a stormy forecast, check your airline's travel waivers.
| Date | Departures | Cancelled | On time |
|---|---|---|---|
| Mar 7, 2026 | 11 | 18% | 64% |
| Jan 24, 2026 | 10 | 10% | 60% |
| Apr 28, 2026 | 11 | 9% | 82% |
| Mar 21, 2026 | 12 | 8% | 67% |
| Feb 12, 2026 | 12 | 8% | 58% |
| Mar 12, 2026 | 12 | 8% | 58% |
| Feb 19, 2026 | 12 | 8% | 67% |
| Feb 17, 2026 | 12 | 8% | 42% |
| Nov 20, 2025 | 13 | 8% | 92% |
| May 19, 2026 | 13 | 8% | 77% |
Last flights of the day
The last flight of the day is a different bet. Across routes from IDA, each airline's final departure was cancelled 0.4% of the time, against 0.5% for its earlier flights, about the same. 1.2% of last flights landed 3+ hours late. The riskiest last flight out was American Airlines to Dallas (0.6% cancelled).
| Last flight to | Airline | Leaves | Cancelled | 3h+ late | On time |
|---|---|---|---|---|---|
| DFW Dallas | American Airlines | 2:20 p.m. | 0.6% | 3.0% | 56% |
| DEN Denver | United Airlines | 5:54 p.m. | 0.5% | 1.4% | 73% |
| SLC Salt Lake City | Delta Air Lines | 7:00 p.m. | 0.3% | 0.8% | 91% |
| SEA Seattle | Alaska Airlines | 1:43 p.m. | 0.3% | 0.6% | 79% |
Each airline's last scheduled departure of the day on a route, on days it flies the route at least twice; past 12 months. Riskiest first.
Tips for flying out of IDA
- Book the earliest departure you can live with. At IDA the 6 a.m. flights do best.
- Traveling in July? Leave extra slack for anything that can't move: cruises, weddings, the last connection of the day.
- Choosing between airlines? Delta Air Lines has the better record here.
- Delayed already? Most delays at IDA come from the airlines themselves. If your inbound plane is late, your flight will be too, whatever the board says.
Routes from IDA
Where you're going matters too. From IDA, the most reliable busy route was to Salt Lake City (SLC, 91% on time) and the least reliable to Denver (DEN, 80%). Flights into congested airports inherit their delays: an air traffic program at the destination holds planes on the ground here.
Least reliable first. Routes with at least 365 flights a year.
| To | Flights | On time | Cancelled | Typical arrival |
|---|---|---|---|---|
| DFW Dallas | 556 | 74% | 1.6% | −9 min |
| DEN Denver | 1,664 | 80% | 0.4% | −11 min |
| SEA Seattle | 721 | 84% | 0.4% | −5 min |
| SLC Salt Lake City | 1,195 | 91% | 0.4% | −11 min |
Flights into IDA
Arriving rather than leaving? These are the routes into Idaho Falls, least reliable first. The weakest is from Dallas (77% on time).
| From | Flights | On time | Cancelled |
|---|---|---|---|
| DFW Dallas | 555 | 77% | 1.3% |
| SEA Seattle | 721 | 81% | 0.4% |
| DEN Denver | 1,663 | 82% | 0.3% |
| SLC Salt Lake City | 1,195 | 89% | 0.4% |
Questions about IDA delays
What is the best time to fly out of IDA?
Flights scheduled at 6 a.m.: over the past year 89% of IDA departures at that hour arrived on time, against 65% at 4 p.m., the worst hour.
What month has the most flight delays at IDA?
July (77% on time). November is the best month (86%).
Which airline is most on time at IDA?
Delta Air Lines: 91% of its IDA departures arrived on time over the past year. United Airlines had the weakest record at 80%.
Why are flights delayed at IDA?
The biggest cause was the airlines themselves (50% of delay minutes): crew, maintenance, cleaning, fueling and baggage. Then late-arriving aircraft (25%).
How often are flights cancelled at IDA?
0.6% of scheduled departures over the past 12 months, peaking in January at 1.4%.
Hours are scheduled local departure times. "On time" means arriving less than 15 minutes late at the destination; cancelled and diverted flights count as not on time. Method.