Best time to fly out of Glacier Park (FCA)

The early-flight folk wisdom holds up at Glacier Park: departures in the Before 6am band left on time 92.8% of the time, against 75.6% in the 2–4pm band. These are historical odds, not forecasts. The records say what happened on this schedule over three years; they know nothing about tomorrow’s thunderstorm.

Data through June 2026 · Bureau of Transportation Statistics

On-time rate by hour and day

On this page, “on time” means a departure that pushed back less than 15 minutes behind its scheduled time — the Bureau of Transportation Statistics definition, and the one airlines are held to.

Share of departures that left on time, by hour band and day of week.
Departure time MonTueWedThuFriSatSun
Before 6am 92 93 91 93 93 95 93
6–8am 92 91 96 94 93 90 93
8–10am
10am–12pm 81 90 83 88 85 86 88
12–2pm 86 88 84 86 82 81 83
2–4pm 76 77 77 77 81 69 75
4–6pm 76 78 80 77 77 80 75
6–8pm 86 86
8–10pm
10pm–12am
fewer left on time more left on time

The steadiest stretch at FCA was Before 6am — 92.8% of departures left on time across 1,153 flights. The weakest was 2–4pm at 75.6%. 6–8am departures from FCA left on time 92.6% of the time across 1,573 flights; 6–8pm departures, 85.9% across 213. That is a gap of 6.7 points, and it is the whole case for the early flight.

The year at FCA

June was the hard month at FCA: 78.2% of departures left on time, across 1,562 flights. November was the easy one at 91.1%. Each month pools three years of that month, so a single bad week does not decide it.

Share of departures that left on time, by calendar month. Best month in green, worst in amber. The hairline sits at the overall rate, 83.5%.
Departure on-time share at FCA by calendar month
Month Share departures that left on time Flights
January 79.6% 761
February 85.7% 669
March 89% 779
April 90.5% 613
May 84.5% 906
June 78.2% 1,562
July 79.4% 1,685
August 80.2% 1,620
September 87.7% 1,192
October 90.1% 806
November 91.1% 591
December 80.4% 785

Airlines at FCA

Every airline with at least 100 departures from FCA, busiest first. These are that airline’s departures from this airport only — its record across the country sits on its own page.

Airline Left on time Typical delay Cancelled Departures
SkyWest Airlines 87.8% 78 min 0.7% 4,533
United Airlines 82.4% 99 min 0.8% 2,864
Delta Air Lines 88% 109 min 0.6% 2,489
American Airlines 68.3% 118 min 0.7% 1,221
Allegiant Air 74% 99 min 0.8% 728
Envoy Air 70.1% 64 min 0% 134

What delays out of FCA were put down to

Airlines file a reason with every arrival running 15 minutes late or more. Across 2,149 flights that departed FCA and ran 15 minutes late or more, the delay minutes break down with 36.9% put down to airline operations and 32% to late-arriving aircraft.

Late-arriving aircraft 32% Airline operations 36.9% Air traffic & airport volume 20.7% Severe weather 10.4% Security 0.1%
  • Late-arriving aircraft 32%
  • Airline operations 36.9%
  • Air traffic & airport volume 20.7%
  • Severe weather 10.4%
  • Security 0.1%

Late-arriving aircraft is the knock-on category: the plane came in late, so it went out late again. It is why a 7am problem in Newark is still a problem in Denver at dinnertime, and why it is usually the biggest slice on the bar.

If you are connecting through FCA

Of 11,970 scheduled arrivals into FCA, 81.4% reached the gate less than 15 minutes behind schedule. Of the 2,117 arrivals that ran late, 60.8% were no more than 45 minutes behind — which is the difference between a tight connection and a new boarding pass.

Work out a specific layover — pick the airport and the minutes you have, and the tool reads the same arrival records back as a share.

Busiest routes out of FCA

Ranked by flights, with the share that arrived on time at the far end. Where a route carries enough flights for a page of its own the chip goes there; otherwise it goes to the destination airport.

FCA in one number

Glacier Park (FCA)

Rank 159 of 363 US airports by departures. Steadiest stretch of the day: Before 6am. Hardest month: June.

July 2023–June 2026 · 11,884 departures flown

83.5% of departures left on time

Questions about FCA

What is the best time of day to fly out of Glacier Park?
Before 6am. Departures in that band left on time 92.8% of the time across 1,153 flights, July 2023 through June 2026 — the best of the ten bands in the day. The 2–4pm band was the weakest at 75.6%.
Is the early flight out of FCA really more reliable?
6–8am departures from FCA left on time 92.6% of the time across 1,573 flights; 6–8pm departures, 85.9% across 213. That is a gap of 6.7 points, and it is the whole case for the early flight.
What is the worst month to fly out of FCA?
June: 78.2% of the departures that flew left on time, with 1,562 scheduled. November was the other end of the year at 91.1%. Each figure pools three years of that calendar month.
Which airline is most on time at FCA?
Delta Air Lines — 88% of its 2,489 departures from FCA left on time. American Airlines sat at the other end at 68.3% over 1,221 flights. Only airlines with at least 100 departures here are ranked.
How often are flights cancelled at FCA?
0.7% of scheduled departures were cancelled over July 2023 through June 2026. Cancellations are counted against everything scheduled, not against everything that flew — a rate that looks small still adds up to real people in a rebooking line.