BTS DATA COMPLETE THROUGH JUNE 2026HISTORICAL ODDS · NOT LIVE FLIGHT STATUS
DelayOddsKnow the route before you book
IAD→PWM

Washington, DC (IAD) to Portland, ME (PWM) flight delay odds

85.6% of 801 official scheduled IAD-to-PWM flights arrived on time; 7.1% arrived at least 30 minutes late and 2.2% were cancelled during July 2025–June 2026.

Source: U.S. Bureau of Transportation Statistics · Reporting window: July 2025–June 2026 · Updated September 16, 2026

HISTORICAL ROUTE SIGNALGenerally reliable
85.6%arrived on time
7.1%30+ min late
2.2%cancelled
801scheduled flights
Based on July 2025–June 2026; on time means arrival less than 15 minutes late.
60+ minutes late4.2%all scheduled flights
120+ minutes late2.7%all scheduled flights
Diverted0.0%did not reach as scheduled
Average arrival+0.0 mincompleted flights

Which departure time was most reliable for IAD to PWM?

Among qualifying IAD-to-PWM departure window results, Early morning had the highest on-time rate: 94.6% of 185 flights. Night was lowest at 72.3% across 141 flights.

Departure windowFlightsOn time30+ minCancelled
Early morning18594.6%2.7%1.1%
Afternoon29189.0%4.5%1.7%
Evening18481.5%10.9%2.2%
Night14172.3%13.5%5.0%

Which weekday was most reliable for IAD to PWM?

Among qualifying IAD-to-PWM weekday results, Friday had the highest on-time rate: 88.4% of 121 flights. Monday was lowest at 83.3% across 120 flights.

DayFlightsOn time30+ minCancelled
Monday12083.3%5.8%4.2%
Tuesday11184.7%4.5%4.5%
Wednesday11085.5%9.1%1.8%
Thursday12284.4%10.7%1.6%
Friday12188.4%7.4%0.0%
Saturday9787.6%5.2%2.1%
Sunday12085.8%6.7%1.7%

Which airline was most reliable for IAD to PWM?

Among qualifying IAD-to-PWM airline results, Republic Airways had the highest on-time rate: 85.8% of 760 flights. United Airlines was lowest at 82.9% across 41 flights.

AirlineFlightsOn time30+ minCancelled
Republic Airways76085.8%7.1%2.4%
United Airlines4182.9%7.3%0.0%

Which month was most reliable for IAD to PWM?

Among qualifying IAD-to-PWM month results, May 2026 had the highest on-time rate: 92.1% of 114 flights. July 2025 was lowest at 68.3% across 123 flights.

MonthFlightsOn time30+ minCancelled
July 202512368.3%16.3%8.9%
August 202510890.7%4.6%0.9%
September 20259491.5%3.2%1.1%
October 202510089.0%7.0%0.0%
November 20255589.1%5.5%1.8%
December 20253271.9%15.6%0.0%
January 20263281.2%6.2%3.1%
February 20262889.3%3.6%3.6%
May 202611492.1%4.4%0.9%
June 202610787.9%5.6%0.9%

What drove IAD to PWM delay minutes?

Airline was the largest recorded IAD-to-PWM delay category, accounting for 42.1% of 8,851 BTS-attributed delay minutes during July 2025–June 2026.

Airline42.1%
Late aircraft37.5%
National airspace15.9%
Weather4.5%
Security0.0%
This is historical evidence, not a forecast.

Weather, schedules and operations change. For a trip you have already booked, use the airline or airport for live status.