Route on-time record
BOS to IAD: most on-time flights and the best time to fly
Boston (Boston Logan International Airport) to Dulles (Washington Dulles International Airport). 1,490 nonstop flights in Jun 2025 to May 2026, 82% arrived within 15 minutes and 1.9% were cancelled. The most reliable flight number was United 1734 at 5:45 AM.
Flying on a specific date? We’ll adjust for the month, the weekday and the forecast.
BOS → IAD
Boston to Dulles: 1,490 nonstop flights a year
On time (12 months)
82%
Cancelled
1.9%
avg delay 14 min
Best time to leave
Before 9 AM
97% on time vs 67% 6 to 9 PM
Most reliable airline
United
81% chance on time
Lowest nonstop fare seen in the next two months: $60 (United 1734 on 2026-11-15). 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 1734
5:45 AM → 7:25 AM1h 40m nonstop
Local times, typical schedule. Last flown 2026-05-31.
95%
chance on time
- On time (history)
- 97%
- Cancelled
- 1.7%
- Avg arrival delay
- 2 min
- Arrived on time 97% of the time (339 flights, Jun 2025 to May 2026).
- Leaves in this route's most on-time window (Before 9 AM: 97% on time; 6 to 9 PM: 67%).
- Departs outside BOS's trouble window (noon to 6 PM, when 79% of its 196 ground stops and delay programs started).
Strong track record · 339 flights
Find United 1734 fares Opens this date on Aviasales#2 · United 2098
9:30 AM → 11:13 AM1h 43m nonstop
Local times, typical schedule. Last flown 2026-05-31.
89%
chance on time
- On time (history)
- 91%
- Cancelled
- 2.4%
- Avg arrival delay
- 6 min
- Arrived on time 91% of the time (279 flights, Jun 2025 to May 2026).
- Departs outside BOS's trouble window (noon to 6 PM, when 79% of its 196 ground stops and delay programs started).
Strong track record · 279 flights
Find United 2098 fares Opens this date on Aviasales#3 · United 721
2:15 PM → 4:23 PM1h 46m nonstop
Local times, typical schedule. Last flown 2026-05-31.
73%
chance on time
- On time (history)
- 76%
- Cancelled
- 2.6%
- Avg arrival delay
- 19 min
- Arrived on time 76% of the time (302 flights, Jun 2025 to May 2026).
- Departs inside BOS's trouble window: 79% of its 196 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 · 302 flights
Find United 721 fares Opens this date on Aviasales#4 · United 2136
7:27 PM → 9:16 PM1h 46m nonstop
Local times, typical schedule. Last flown 2026-05-31.
66%
chance on time
- On time (history)
- 67%
- Cancelled
- 2.1%
- Avg arrival delay
- 29 min
- Arrived on time 67% of the time (329 flights, Jun 2025 to May 2026).
- Leaves in this route's least on-time window (6 to 9 PM: 67% on time; Before 9 AM: 97%).
- Departs outside BOS's trouble window (noon to 6 PM, when 79% of its 196 ground stops and delay programs started).
- 62% of its delay minutes came from the plane arriving late from an earlier flight.
Strong track record · 329 flights
Find United 2136 fares Opens this date on Aviasales
Airlines on this route
Season-adjusted chance of operating and arriving on time.
- United Airlines81%
1,487 flights · 82% on time as flown · 1.9% cancel
On time by departure time
All airlines, scheduled local departure, Jun 2025 to May 2026.
- Before 9 AM97%
346 flights · avg delay 2 min
- 9 AM to noon92%
368 flights · avg delay 5 min
- Noon to 3 PM75%
420 flights · avg delay 21 min
- 6 to 9 PM67%
356 flights · avg delay 28 min
Best day: Saturday (86%). Worst: Friday (80%).
Smarter routing
Nearby airports that run more on time
MHT → BWI 86% chance on time
Manchester-Boston Regional Airport to Baltimore/Washington International Thurgood Marshall Airport · 1,710 flights a year · 90 mi from your airports · yours: 81%
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 aircraft49%
- Air traffic control and airport volume31%
- Airline (crew, maintenance, boarding)17%
- Severe weather3%
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
BOS to IAD questions
- What time of day is best to fly BOS to IAD?
- Before 9 AM: 97% of flights arrived on time, against 67% 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 BOS to IAD?
- United, with a season-adjusted 81% chance of operating and arriving on time over 1,487 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 BOS to IAD?
- July (70% on time); the best was February (90%), 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 BOS
- IAD to BOS (return)
- BOS to DCA 74%
- BOS to ORD 72%
- BOS to LGA 77%
- BOS to JFK 75%
- BOS to PHL 76%
- BOS to ATL 78%
- BOS to LAX 76%
- BOS to MCO 70%
- BOS to SFO 75%
- BOS to CLT 82%
- BOS to DEN 76%
- BOS to EWR 74%
Live status: FAA delays and ground stops