Route on-time record
IAH to IAD: most on-time flights and the best time to fly
Houston (George Bush Intercontinental Airport) to Dulles (Washington Dulles International Airport). 1,862 nonstop flights in Jun 2025 to May 2026, 80% arrived within 15 minutes and 0.6% were cancelled. The most reliable flight number was United 1549 at 7:25 AM.
Flying on a specific date? We’ll adjust for the month, the weekday and the forecast.
IAH → IAD
Houston to Dulles: 1,862 nonstop flights a year
On time (12 months)
80%
Cancelled
0.6%
avg delay 14 min
Best time to leave
Before 9 AM
91% on time vs 72% 6 to 9 PM
Most reliable airline
United
79% chance on time
Lowest nonstop fare seen in the next two months: $298 (United 750 on 2026-10-26). 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 · United 1549
7:25 AM → 11:28 AM3h 08m nonstop
Local times, typical schedule. Last flown 2026-05-31.
90%
chance on time
- On time (history)
- 92%
- Cancelled
- 0.7%
- Avg arrival delay
- 4 min
- Arrived on time 92% of the time (283 flights, Jun 2025 to May 2026).
- Leaves in this route's most on-time window (Before 9 AM: 91% on time; 6 to 9 PM: 72%).
- Departs outside IAH's trouble window (noon to 6 PM, when 60% of its 92 ground stops and delay programs started).
Strong track record · 283 flights
Find United 1549 fares Opens this date on Aviasales#2 · United 1478
2:31 PM → 6:50 PM3h 19m nonstop
Local times, typical schedule. Last flown 2026-05-31.
87%
chance on time
- On time (history)
- 100%
- Cancelled
- 0.0%
- Avg arrival delay
- 2 min
- Arrived on time 100% of the time (11 flights, Jun 2025 to May 2026).
- Departs inside IAH's trouble window: 60% of its 92 ground stops and delay programs started between noon and 6 PM.
- Lands inside IAD's trouble window: 75% of its 63 ground stops and delay programs started between 1 PM and 7 PM.
- Short track record (11 flights), so its score leans on the airline's record at this hour.
Limited track record · 11 flights
Find United 1478 fares Opens this date on Aviasales#3 · United 2366
12:10 PM → 4:22 PM3h 12m nonstop
Local times, typical schedule. Last flown 2026-05-31.
80%
chance on time
- On time (history)
- 82%
- Cancelled
- 0.3%
- Avg arrival delay
- 10 min
- Arrived on time 82% of the time (310 flights, Jun 2025 to May 2026).
- Departs inside IAH's trouble window: 60% of its 92 ground stops and delay programs started between noon and 6 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 · 310 flights
Find United 2366 fares Opens this date on Aviasales#4 · United 2388
4:35 PM → 8:46 PM3h 11m nonstop
Local times, typical schedule. Last flown 2026-05-31.
77%
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).
- Departs inside IAH's trouble window: 60% of its 92 ground stops and delay programs started between noon and 6 PM.
- Short track record (11 flights), so its score leans on the airline's record at this hour.
Limited track record · 11 flights
Find United 2388 fares Opens this date on Aviasales#5 · United 1788
4:47 PM → 8:56 PM3h 09m nonstop
Local times, typical schedule. Last flown 2026-05-20.
76%
chance on time
- On time (history)
- 76%
- Cancelled
- 0.3%
- Avg arrival delay
- 18 min
- Arrived on time 76% of the time (353 flights, Jun 2025 to May 2026).
- Departs inside IAH's trouble window: 60% of its 92 ground stops and delay programs started between noon and 6 PM.
Strong track record · 353 flights
Find United 1788 fares Opens this date on Aviasales#6 · United 1373
6:33 PM → 10:44 PM3h 10m nonstop
Local times, typical schedule. Last flown 2026-05-31.
73%
chance on time
- On time (history)
- 76%
- Cancelled
- 1.8%
- Avg arrival delay
- 16 min
- Arrived on time 76% of the time (107 flights, Jun 2025 to May 2026).
- Leaves in this route's least on-time window (6 to 9 PM: 72% on time; Before 9 AM: 91%).
- Departs outside IAH's trouble window (noon to 6 PM, when 60% of its 92 ground stops and delay programs started).
Moderate track record · 107 flights
Find United 1373 fares Opens this date on Aviasales#7 · United 1887
7:50 PM → 11:59 PM3h 09m nonstop
Local times, typical schedule. Last flown 2026-05-31.
73%
chance on time
- On time (history)
- 69%
- Cancelled
- 0.5%
- Avg arrival delay
- 23 min
- Arrived on time 69% of the time (183 flights, Jun 2025 to May 2026).
- Leaves in this route's least on-time window (6 to 9 PM: 72% on time; Before 9 AM: 91%).
- Departs outside IAH's trouble window (noon to 6 PM, when 60% of its 92 ground stops and delay programs started).
Moderate track record · 183 flights
Find United 1887 fares Opens this date on Aviasales
Airlines on this route
Season-adjusted chance of operating and arriving on time.
- United Airlines79%
1,862 flights · 80% on time as flown · 0.6% cancel
On time by departure time
All airlines, scheduled local departure, Jun 2025 to May 2026.
- Before 9 AM91%
364 flights · avg delay 5 min
- 9 AM to noon83%
60 flights · avg delay 13 min
- Noon to 3 PM82%
412 flights · avg delay 12 min
- 3 to 6 PM77%
407 flights · avg delay 18 min
- 6 to 9 PM72%
619 flights · avg delay 19 min
Best day: Tuesday (81%). Worst: Friday (75%).
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.
What delays this route
- Late-arriving aircraft35%
- Airline (crew, maintenance, boarding)31%
- Air traffic control and airport volume22%
- Severe weather12%
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
IAH to IAD questions
- What time of day is best to fly IAH to IAD?
- Before 9 AM: 91% of flights arrived on time, against 72% for departures 6 to 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 IAH to IAD?
- United, with a season-adjusted 79% chance of operating and arriving on time over 1,862 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 IAH to IAD?
- July (61% on time); the best was October (87%), 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 IAH
- IAD to IAH (return)
- IAH to ORD 75%
- IAH to DFW 75%
- IAH to LAX 83%
- IAH to ATL 77%
- IAH to DEN 81%
- IAH to LGA 72%
- IAH to MIA 78%
- IAH to EWR 74%
- IAH to MCO 81%
- IAH to SFO 79%
- IAH to LAS 82%
- IAH to DCA 75%
Live status: FAA delays and ground stops