Best time to fly out of Austin Straubel (GRB)
The early-flight folk wisdom holds up at Austin Straubel: departures in the 6–8am band left on time 91.4% of the time, against 75.5% in the 4–6pm 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.
| Departure time | Mon | Tue | Wed | Thu | Fri | Sat | Sun |
|---|---|---|---|---|---|---|---|
| Before 6am | 87 | 93 | 92 | 90 | 85 | 90 | 91 |
| 6–8am | 92 | 92 | 92 | 90 | 92 | 90 | 92 |
| 8–10am | 88 | 85 | – | 85 | 83 | 88 | 77 |
| 10am–12pm | 78 | 79 | 85 | 84 | 78 | 86 | 78 |
| 12–2pm | 82 | 88 | 80 | 82 | 81 | 84 | 83 |
| 2–4pm | 80 | 79 | 79 | 75 | 82 | 80 | 64 |
| 4–6pm | 79 | 79 | 78 | 72 | 75 | 75 | 72 |
| 6–8pm | – | – | – | – | – | – | – |
| 8–10pm | – | – | – | – | – | – | – |
| 10pm–12am | – | – | – | – | – | – | – |
The steadiest stretch at GRB was 6–8am — 91.4% of departures left on time across 3,485 flights. The weakest was 4–6pm at 75.5%.
The year at GRB
January was the hard month at GRB: 75.8% of departures left on time, across 959 flights. October was the easy one at 90.3%. Each month pools three years of that month, so a single bad week does not decide it.
| Month | Share departures that left on time | Flights |
|---|---|---|
| January | 75.8% | 959 |
| February | 83.7% | 924 |
| March | 79.9% | 1,186 |
| April | 85.6% | 1,282 |
| May | 84% | 1,205 |
| June | 83.8% | 1,210 |
| July | 80.3% | 953 |
| August | 84% | 1,107 |
| September | 85.6% | 1,037 |
| October | 90.3% | 1,121 |
| November | 86.4% | 1,082 |
| December | 77.8% | 989 |
Airlines at GRB
Every airline with at least 100 departures from GRB, 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 | 82.6% | 107 min | 1.7% | 8,734 |
| Envoy Air | 81.5% | 68 min | 2.8% | 2,159 |
| Delta Air Lines | 87.6% | 123 min | 1.2% | 1,304 |
| Republic Airways | 90.2% | 85 min | 2.8% | 464 |
| Frontier Airlines | 79.7% | 130 min | 2.3% | 217 |
| Endeavor Air | 93.8% | — | 0% | 177 |
A dash under typical delay means fewer than 30 of that airline’s departures ran 15 minutes late or more — too few to average.
What delays out of GRB were put down to
Airlines file a reason with every arrival running 15 minutes late or more. Across 2,544 flights that departed GRB and ran 15 minutes late or more, the delay minutes break down with 46.4% put down to airline operations and 23.9% to late-arriving aircraft.
- Late-arriving aircraft 23.9%
- Airline operations 46.4%
- Air traffic & airport volume 15.5%
- Severe weather 14.2%
- 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 GRB
Of 13,055 scheduled arrivals into GRB, 74.8% reached the gate less than 15 minutes behind schedule. Of the 3,023 arrivals that ran late, 48.9% 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 GRB
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.
- ORD 75.3% on time · 6,239 flights
- MSP 84% on time · 2,791 flights
- DTW 84.7% on time · 2,684 flights
- ATL 86.4% on time · 1,102 flights
- DEN 75.7% on time · 171 flights
- MCO Not enough flights to say · 47 flights
- CLT Not enough flights to say · 4 flights
- LGA Not enough flights to say · 3 flights
- PHX Not enough flights to say · 3 flights
- SLC Not enough flights to say · 2 flights
GRB in one number
Austin Straubel (GRB)
Rank 151 of 363 US airports by departures. Steadiest stretch of the day: 6–8am. Hardest month: January.
Questions about GRB
- What is the best time of day to fly out of Austin Straubel?
- 6–8am. Departures in that band left on time 91.4% of the time across 3,485 flights, July 2023 through June 2026 — the best of the ten bands in the day. The 4–6pm band was the weakest at 75.5%.
- What is the worst month to fly out of GRB?
- January: 75.8% of the departures that flew left on time, with 959 scheduled. October was the other end of the year at 90.3%. Each figure pools three years of that calendar month.
- Which airline is most on time at GRB?
- Endeavor Air — 93.8% of its 177 departures from GRB left on time. Frontier Airlines sat at the other end at 79.7% over 217 flights. Only airlines with at least 100 departures here are ranked.
- How often are flights cancelled at GRB?
- 1.9% 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.