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.
DEN → DCA
Denver to Washington: 1,350 nonstop flights a year
On time (12 months)
80%
Cancelled
0.7%
avg delay 16 min
Best time to leave
Before 9 AM
95% on time vs 63% 3 to 6 PM
Most reliable airline
United
88% chance on time
Lowest nonstop fare seen in the next two months: $161 (Frontier 686 on 2026-11-11). 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 · Frontier 686
7:35 AM → 12:59 PM3h 27m nonstop
Local times, typical schedule. Last flown 2026-05-31.
93%
chance on time
- On time (history)
- 95%
- Cancelled
- 0.6%
- Avg arrival delay
- 3 min
- Arrived on time 95% of the time (310 flights, Jun 2025 to May 2026).
- Leaves in this route's most on-time window (Before 9 AM: 95% on time; 3 to 6 PM: 63%).
- Departs outside DEN's trouble window (2 PM to 8 PM, when 79% of its 174 ground stops and delay programs started).
Strong track record · 310 flights
Find Frontier 686 fares Opens this date on Aviasales#2 · United 789
9:35 AM → 2:59 PM3h 24m nonstop
Local times, typical schedule. Last flown 2026-05-31.
91%
chance on time
- On time (history)
- 92%
- Cancelled
- 0.6%
- Avg arrival delay
- 5 min
- Arrived on time 92% of the time (164 flights, Jun 2025 to May 2026).
- Departs outside DEN's trouble window (2 PM to 8 PM, when 79% of its 174 ground stops and delay programs started).
- Lands inside DCA's trouble window: 63% of its 194 ground stops and delay programs started between 1 PM and 7 PM.
Moderate track record · 164 flights
Find United 789 fares Opens this date on Aviasales#3 · Frontier 688
11:34 AM → 4:59 PM3h 25m nonstop
Local times, typical schedule. Last flown 2026-05-31.
74%
chance on time
- On time (history)
- 75%
- Cancelled
- 1.3%
- Avg arrival delay
- 20 min
- Arrived on time 75% of the time (304 flights, Jun 2025 to May 2026).
- Departs outside DEN's trouble window (2 PM to 8 PM, when 79% of its 174 ground stops and delay programs started).
- Lands inside DCA's trouble window: 63% of its 194 ground stops and delay programs started between 1 PM and 7 PM.
Strong track record · 304 flights
Find Frontier 688 fares Opens this date on Aviasales#4 · Frontier 690
4:36 PM → 9:59 PM3h 23m nonstop
Local times, typical schedule. Last flown 2026-05-31.
62%
chance on time
- On time (history)
- 63%
- Cancelled
- 0.6%
- Avg arrival delay
- 32 min
- Arrived on time 63% of the time (357 flights, Jun 2025 to May 2026).
- Leaves in this route's least on-time window (3 to 6 PM: 63% on time; Before 9 AM: 95%).
- Departs inside DEN's trouble window: 79% of its 174 ground stops and delay programs started between 2 PM and 8 PM.
Strong track record · 357 flights
Find Frontier 690 fares Opens this date on Aviasales
Airlines on this route
Season-adjusted chance of operating and arriving on time.
- United Airlines88%
365 flights · 89% on time as flown · 0.4% cancel
- Frontier Airlines76%
985 flights · 77% on time as flown · 0.8% cancel
On time by departure time
All airlines, scheduled local departure, Jun 2025 to May 2026.
- Before 9 AM95%
312 flights · avg delay 3 min
- 9 AM to noon83%
679 flights · avg delay 13 min
- 3 to 6 PM63%
356 flights · avg delay 32 min
Best day: Saturday (83%). Worst: Monday (75%).
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