Skip to content

All Products

Aviation Intelligence

Alerts & Airspace

Free Pilot Tools & Widgets

RC Aviation

Games & Learning

Weather Research & More

Pilot Resources

My Airports

Your shortcuts, saved on this device. Search to add an airport.

No airports saved yet. Add the fields you visit most.

Ask ATIS

Route on-time record

ORD to BUF: most on-time flights and the best time to fly

Chicago (Chicago O'Hare International Airport) to Buffalo (Buffalo Niagara International Airport). 2,175 nonstop flights in Jun 2025 to May 2026, 71% arrived within 15 minutes and 2.8% were cancelled. The most reliable flight number was United 1079 at 7:00 AM.

Flying on a specific date? We’ll adjust for the month, the weekday and the forecast.

ORD → BUF

Chicago to Buffalo: 2,175 nonstop flights a year

On time (12 months)

71%

Cancelled

2.8%

avg delay 24 min

Best time to leave

Before 9 AM

85% on time vs 42% after 9 PM

Most reliable airline

Envoy

77% chance on time

Check ORD to BUF fares

Lowest nonstop fare seen in the next two months: $123 (United 265 on 2026-10-21). Fares open on our travel partner (Aviasales). Pick the flight number you chose here.

Most reliable nonstop flights

Ranked by the chance the flight operates and arrives within 15 minutes of schedule, from Jun 2025 to May 2026 records.

  1. #1 · United 1079

    7:00 AM → 9:42 AM1h 42m nonstop

    Local times, typical schedule. Last flown 2026-05-20.

    85%

    chance on time

    On time (history)
    90%
    Cancelled
    0.0%
    Avg arrival delay
    6 min
    • Arrived on time 90% of the time (20 flights, Jun 2025 to May 2026).
    • Leaves in this route's most on-time window (Before 9 AM: 85% on time; After 9 PM: 42%).
    • Departs outside ORD's trouble window (2 PM to 8 PM, when 44% of its 243 ground stops and delay programs started).
    • Short track record (20 flights), so its score leans on the airline's record at this hour.

    Limited track record · 20 flights

    Find United 1079 fares Opens this date on Aviasales

  2. #2 · Republic 4420 · sold as American Eagle, Delta Connection or United Express

    9:05 AM → 11:49 AM1h 44m nonstop

    Local times, typical schedule. Last flown 2026-04-06.

    79%

    chance on time

    On time (history)
    85%
    Cancelled
    0.0%
    Avg arrival delay
    20 min
    • Arrived on time 85% of the time (26 flights, Jun 2025 to May 2026).
    • Departs outside ORD's trouble window (2 PM to 8 PM, when 44% of its 243 ground stops and delay programs started).
    • 72% of its delay minutes came from the plane arriving late from an earlier flight.
    • Short track record (26 flights), so its score leans on the airline's record at this hour.

    Limited track record · 26 flights

    Find 9:05 AM flight fares Opens this date on Aviasales

  3. #3 · Republic 4423 · sold as American Eagle, Delta Connection or United Express

    2:40 PM → 5:30 PM1h 50m nonstop

    Local times, typical schedule. Last flown 2026-05-20.

    79%

    chance on time

    On time (history)
    86%
    Cancelled
    2.3%
    Avg arrival delay
    6 min
    • Arrived on time 86% of the time (42 flights, Jun 2025 to May 2026).
    • Departs inside ORD's trouble window: 44% of its 243 ground stops and delay programs started between 2 PM and 8 PM.
    • Short track record (42 flights), so its score leans on the airline's record at this hour.

    Limited track record · 42 flights

    Find 2:40 PM flight fares Opens this date on Aviasales

  4. #4 · American 2182

    8:10 AM → 10:51 AM1h 41m nonstop

    Local times, typical schedule. Last flown 2026-05-20.

    77%

    chance on time

    On time (history)
    84%
    Cancelled
    0.0%
    Avg arrival delay
    8 min
    • Arrived on time 84% of the time (44 flights, Jun 2025 to May 2026).
    • Never cancelled in 44 scheduled flights.
    • Leaves in this route's most on-time window (Before 9 AM: 85% on time; After 9 PM: 42%).
    • Departs outside ORD's trouble window (2 PM to 8 PM, when 44% of its 243 ground stops and delay programs started).

    Limited track record · 44 flights

    Find American 2182 fares Opens this date on Aviasales

  5. #5 · Envoy 3382 · sold as American Eagle

    1:45 PM → 4:23 PM1h 38m nonstop

    Local times, typical schedule. Last flown 2026-04-06.

    75%

    chance on time

    On time (history)
    76%
    Cancelled
    3.8%
    Avg arrival delay
    15 min
    • Arrived on time 76% of the time (76 flights, Jun 2025 to May 2026).
    • Cancelled 3.8% of the time (3 of 79).
    • Departs outside ORD's trouble window (2 PM to 8 PM, when 44% of its 243 ground stops and delay programs started).
    • 50% of its delay minutes came from the plane arriving late from an earlier flight.

    Moderate track record · 76 flights

    Find 1:45 PM flight fares Opens this date on Aviasales

  6. #6 · United 2226

    2:13 PM → 4:54 PM1h 41m nonstop

    Local times, typical schedule. Last flown 2026-05-31.

    75%

    chance on time

    On time (history)
    74%
    Cancelled
    0.0%
    Avg arrival delay
    14 min
    • Arrived on time 74% of the time (27 flights, Jun 2025 to May 2026).
    • Departs inside ORD's trouble window: 44% of its 243 ground stops and delay programs started between 2 PM and 8 PM.
    • Short track record (27 flights), so its score leans on the airline's record at this hour.

    Limited track record · 27 flights

    Find United 2226 fares Opens this date on Aviasales

  7. #7 · Republic 3491 · sold as American Eagle, Delta Connection or United Express

    1:55 PM → 4:42 PM1h 47m nonstop

    Local times, typical schedule. Last flown 2026-03-27.

    74%

    chance on time

    On time (history)
    80%
    Cancelled
    11.8%
    Avg arrival delay
    11 min
    • Arrived on time 80% of the time (15 flights, Jun 2025 to May 2026).
    • Departs outside ORD's trouble window (2 PM to 8 PM, when 44% of its 243 ground stops and delay programs started).
    • 65% of its delay minutes came from the plane arriving late from an earlier flight.
    • Short track record (15 flights), so its score leans on the airline's record at this hour.

    Limited track record · 15 flights

    Find 1:55 PM flight fares Opens this date on Aviasales

  8. #8 · Republic 4413 · sold as American Eagle, Delta Connection or United Express

    6:40 AM → 9:31 AM1h 51m nonstop

    Local times, typical schedule. Last flown 2026-05-31.

    73%

    chance on time

    On time (history)
    82%
    Cancelled
    0.0%
    Avg arrival delay
    10 min
    • Arrived on time 82% of the time (11 flights, Jun 2025 to May 2026).
    • Leaves in this route's most on-time window (Before 9 AM: 85% on time; After 9 PM: 42%).
    • Departs outside ORD's trouble window (2 PM to 8 PM, when 44% of its 243 ground stops and delay programs started).
    • Short track record (11 flights), so its score leans on the airline's record at this hour.

    Limited track record · 11 flights

    Find 6:40 AM flight fares Opens this date on Aviasales

  9. #9 · Republic 4349 · sold as American Eagle, Delta Connection or United Express

    2:48 PM → 5:29 PM1h 41m nonstop

    Local times, typical schedule. Last flown 2026-04-06.

    72%

    chance on time

    On time (history)
    72%
    Cancelled
    6.0%
    Avg arrival delay
    15 min
    • Arrived on time 72% of the time (47 flights, Jun 2025 to May 2026).
    • Cancelled 6.0% of the time (3 of 50).
    • Departs inside ORD's trouble window: 44% of its 243 ground stops and delay programs started between 2 PM and 8 PM.
    • Short track record (47 flights), so its score leans on the airline's record at this hour.

    Limited track record · 47 flights

    Find 2:48 PM flight fares Opens this date on Aviasales

  10. #10 · American 2957

    11:40 AM → 2:21 PM1h 41m nonstop

    Local times, typical schedule. Last flown 2026-05-20.

    69%

    chance on time

    On time (history)
    77%
    Cancelled
    2.3%
    Avg arrival delay
    13 min
    • Arrived on time 77% of the time (43 flights, Jun 2025 to May 2026).
    • Departs outside ORD's trouble window (2 PM to 8 PM, when 44% of its 243 ground stops and delay programs started).
    • 69% of its delay minutes came from the plane arriving late from an earlier flight.
    • Short track record (43 flights), so its score leans on the airline's record at this hour.

    Limited track record · 43 flights

    Find American 2957 fares Opens this date on Aviasales

Airlines on this route

Season-adjusted chance of operating and arriving on time.

  • Envoy Air (sold as American Eagle)77%

    472 flights · 80% on time as flown · 2.4% cancel

  • United Airlines72%

    609 flights · 74% on time as flown · 1.3% cancel

  • Republic Airways (sold as American Eagle, Delta Connection or United Express)71%

    336 flights · 73% on time as flown · 4.6% cancel

  • SkyWest Airlines (sold as United Express, Delta Connection, American Eagle or Alaska)61%

    290 flights · 62% on time as flown · 4.6% cancel

  • American Airlines59%

    468 flights · 59% on time as flown · 2.1% cancel

On time by departure time

All airlines, scheduled local departure, Jun 2025 to May 2026.

  • Before 9 AM85%

    447 flights · avg delay 10 min

  • 9 AM to noon74%

    254 flights · avg delay 19 min

  • Noon to 3 PM75%

    668 flights · avg delay 19 min

  • 3 to 6 PM62%

    123 flights · avg delay 36 min

  • 6 to 9 PM58%

    617 flights · avg delay 38 min

  • After 9 PM42%

    66 flights · avg delay 35 min

Best day: Saturday (78%). Worst: Sunday (71%).

Smarter routing

Nearby airports that run more on time

  • MDW → BUF 74% chance on time

    Chicago Midway International Airport to Buffalo Niagara International Airport · 830 flights a year · 15 mi from your airports · yours: 69%

    Rank flightsFares

  • ORD → ROC 73% chance on time

    Chicago O'Hare International Airport to Frederick Douglass Greater Rochester International Airport · 2,275 flights a year · 55 mi from your airports · yours: 69%

    Rank flightsFares

On time by month

All airlines, Jun 2023 to May 2026. Several years per month, so one stormy season doesn't define a month. Travel-month estimates use this seasonal pattern.

J
69
F
77
M
74
A
81
M
75
J
70
J
64
A
72
S
81
O
79
N
82
D
75

What delays this route

  • Late-arriving aircraft47%
  • Airline (crew, maintenance, boarding)28%
  • Air traffic control and airport volume16%
  • Severe weather8%

Share of delay minutes by the cause airlines report to the US DOT.

Historical odds, not a guarantee. Built from the US DOT Bureau of Transportation Statistics on-time reports (Jun 2025 to May 2026), FAA ground stop and delay program advisories, and 20 years of airport weather observations. Covers US airlines that report to the DOT; schedules are flights operated recently, so confirm times when you book. ATIS Alerts is not affiliated with any airline. Fares are what Aviasales travelers saw in recent searches (USD, one way, 1 adult), not live quotes; the partner site shows the current price. Fare links go to our travel partner and may earn us a commission at no cost to you. Affiliate disclosure

ORD to BUF questions

What time of day is best to fly ORD to BUF?
Before 9 AM: 85% of flights arrived on time, against 42% for departures after 9 PM. Later flights inherit delays from earlier ones, so the first departures of the day usually run best.
Which airline is most on time from ORD to BUF?
Envoy, with a season-adjusted 77% chance of operating and arriving on time over 472 flights. The adjustment compares each airline with what the route did in the months it flew, so a carrier that skipped a stormy month gets no free credit.
What is the worst month for delays on ORD to BUF?
July (64% on time); the best was November (82%), averaged over Jun 2023 to May 2026.
Is this a prediction for my flight?
No. These are historical odds from the US DOT on-time reports, FAA advisories and airport weather records. Check your flight status and the FAA delay board on the day you fly.

More routes from ORD

Live status: FAA delays and ground stops