ATIS Alerts Smart Flight Search
Find the flight least likely to be delayed
BetaWe rank real flight numbers by how often they flew and arrived on time over the last 12 months, adjusted for your travel month and departure time, then check nearby airports and calmer connections. US airlines and airports.
MIA → IAD
Miami to Dulles: 668 nonstop flights a year
On time (12 months)
78%
Cancelled
0.9%
avg delay 19 min
Best time to leave
9 AM to noon
85% on time vs 51% 3 to 6 PM
Most reliable airline
United
80% chance on time
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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 · United 2435
1:20 PM → 4:03 PM2h 43m nonstop
Local times, typical schedule. Last flown 2026-05-31.
82%
chance on time
- On time (history)
- 83%
- Cancelled
- 0.3%
- Avg arrival delay
- 16 min
- Arrived on time 83% of the time (326 flights, Jun 2025 to May 2026).
- Departs inside MIA's trouble window: 49% of its 45 ground stops and delay programs started between 1 PM and 7 PM.
- Lands inside IAD's trouble window: 75% of its 63 ground stops and delay programs started between 1 PM and 7 PM.
Strong track record · 326 flights
Find United 2435 fares Opens this date on Aviasales#2 · United 1538
6:00 PM → 8:49 PM2h 50m nonstop
Local times, typical schedule. Last flown 2026-05-20.
78%
chance on time
- On time (history)
- 78%
- Cancelled
- 0.0%
- Avg arrival delay
- 19 min
- Arrived on time 78% of the time (91 flights, Jun 2025 to May 2026).
- Never cancelled in 91 scheduled flights.
- Departs inside MIA's trouble window: 49% of its 45 ground stops and delay programs started between 1 PM and 7 PM.
- 58% of its delay minutes came from the plane arriving late from an earlier flight.
Moderate track record · 91 flights
Find United 1538 fares Opens this date on Aviasales#3 · Frontier 3732
6:33 PM → 9:18 PM2h 45m nonstop
Local times, typical schedule. Last flown 2026-04-12.
67%
chance on time
- On time (history)
- 68%
- Cancelled
- 5.0%
- Avg arrival delay
- 12 min
- Arrived on time 68% of the time (19 flights, Jun 2025 to May 2026).
- Departs inside MIA's trouble window: 49% of its 45 ground stops and delay programs started between 1 PM and 7 PM.
- 60% of its delay minutes came from the plane arriving late from an earlier flight.
- Short track record (19 flights), so its score leans on the airline's record at this hour.
Limited track record · 19 flights
Find Frontier 3732 fares Opens this date on Aviasales
Airlines on this route
Season-adjusted chance of operating and arriving on time.
- United Airlines80%
512 flights · 81% on time as flown · 0.5% cancel
- Frontier Airlines71%
156 flights · 68% on time as flown · 1.7% cancel
On time by departure time
All airlines, scheduled local departure, Jun 2025 to May 2026.
- 9 AM to noon85%
54 flights · avg delay 5 min
- Noon to 3 PM81%
387 flights · avg delay 19 min
- 3 to 6 PM51%
39 flights · avg delay 52 min
- 6 to 9 PM75%
162 flights · avg delay 18 min
Best day: Wednesday (88%). Worst: Sunday (74%).
Smarter routing
Nearby airports that run more on time
FLL → IAD 85% chance on time
Fort Lauderdale Hollywood International Airport to Washington Dulles International Airport · 743 flights a year · 21 mi from your airports · yours: 78%
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