Route on-time record
DCA to SEA: most on-time flights and the best time to fly
Washington (Ronald Reagan Washington National Airport) to Seattle (Seattle–Tacoma International Airport). 1,094 nonstop flights in Jun 2025 to May 2026, 73% arrived within 15 minutes and 1.6% were cancelled. The most reliable flight number was Alaska 1 at 8:00 AM.
Flying on a specific date? We’ll adjust for the month, the weekday and the forecast.
DCA → SEA
Washington to Seattle: 1,094 nonstop flights a year
On time (12 months)
73%
Cancelled
1.6%
avg delay 21 min
Best time to leave
Before 9 AM
80% on time vs 69% 3 to 6 PM
Most reliable airline
Alaska
75% chance on time
Lowest nonstop fare seen in the next two months: $415 (Alaska 1 on 2026-10-29). 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 · Alaska 1
8:00 AM → 11:05 AM6h 05m nonstop
Local times, typical schedule. Last flown 2026-05-31.
79%
chance on time
- On time (history)
- 80%
- Cancelled
- 1.1%
- Avg arrival delay
- 10 min
- Arrived on time 80% of the time (360 flights, Jun 2025 to May 2026).
- Leaves in this route's most on-time window (Before 9 AM: 80% on time; 3 to 6 PM: 69%).
- Departs outside DCA's trouble window (1 PM to 7 PM, when 63% of its 194 ground stops and delay programs started).
Strong track record · 360 flights
Find Alaska 1 fares Opens this date on Aviasales#2 · Alaska 3
5:00 PM → 8:02 PM6h 02m nonstop
Local times, typical schedule. Last flown 2026-05-31.
72%
chance on time
- On time (history)
- 72%
- Cancelled
- 1.1%
- Avg arrival delay
- 18 min
- Arrived on time 72% of the time (358 flights, Jun 2025 to May 2026).
- Leaves in this route's least on-time window (3 to 6 PM: 69% on time; Before 9 AM: 80%).
- Departs inside DCA's trouble window: 63% of its 194 ground stops and delay programs started between 1 PM and 7 PM.
- Lands inside SEA's trouble window: 54% of its 68 ground stops and delay programs started between 4 PM and 10 PM.
Strong track record · 358 flights
Find Alaska 3 fares Opens this date on Aviasales#3 · Delta 786
4:40 PM → 7:34 PM5h 52m nonstop
Local times, typical schedule. Last flown 2026-05-31.
60%
chance on time
- On time (history)
- 61%
- Cancelled
- 3.9%
- Avg arrival delay
- 44 min
- Arrived on time 61% of the time (122 flights, Jun 2025 to May 2026).
- Cancelled 3.9% of the time (5 of 127).
- Leaves in this route's least on-time window (3 to 6 PM: 69% on time; Before 9 AM: 80%).
- Departs inside DCA's trouble window: 63% of its 194 ground stops and delay programs started between 1 PM and 7 PM.
Moderate track record · 122 flights
Find Delta 786 fares Opens this date on Aviasales
Airlines on this route
Season-adjusted chance of operating and arriving on time.
- Alaska Airlines75%
729 flights · 76% on time as flown · 1.2% cancel
- Delta Air Lines65%
365 flights · 66% on time as flown · 2.4% cancel
On time by departure time
All airlines, scheduled local departure, Jun 2025 to May 2026.
- Before 9 AM80%
365 flights · avg delay 10 min
- 3 to 6 PM69%
729 flights · avg delay 26 min
Best day: Saturday (85%). Worst: Thursday (75%).
Smarter routing
Nearby airports that run more on time
IAD → SEA 75% chance on time
Washington Dulles International Airport to Seattle–Tacoma International Airport · 1,926 flights a year · 23 mi from your airports · yours: 72%
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
- Air traffic control and airport volume34%
- Late-arriving aircraft30%
- Airline (crew, maintenance, boarding)25%
- Severe weather11%
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
DCA to SEA questions
- What time of day is best to fly DCA to SEA?
- Before 9 AM: 80% of flights arrived on time, against 69% for departures 3 to 6 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 DCA to SEA?
- Alaska, with a season-adjusted 75% chance of operating and arriving on time over 729 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 DCA to SEA?
- December (69% on time); the best was April (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 DCA
- SEA to DCA (return)
- DCA to BOS 71%
- DCA to ORD 74%
- DCA to ATL 78%
- DCA to LGA 67%
- DCA to MCO 74%
- DCA to BNA 77%
- DCA to MIA 75%
- DCA to DFW 77%
- DCA to IAH 81%
- DCA to DTW 76%
- DCA to CLT 78%
- DCA to MSP 78%
Most on-time flights from DCA on every route →
Live status: FAA delays and ground stops