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

Portland, ME (PWM) to Chicago, IL (ORD) flight delay odds

74.4% of 1,486 official scheduled PWM-to-ORD flights arrived on time; 13.5% arrived at least 30 minutes late and 3.2% 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 SIGNALVariable
74.4%arrived on time
13.5%30+ min late
3.2%cancelled
1,486scheduled flights
Based on July 2025–June 2026; on time means arrival less than 15 minutes late.
60+ minutes late8.0%all scheduled flights
120+ minutes late4.2%all scheduled flights
Diverted0.3%did not reach as scheduled
Average arrival+12.2 mincompleted flights

Which departure time was most reliable for PWM to ORD?

Among qualifying PWM-to-ORD departure window results, Early morning had the highest on-time rate: 86.1% of 482 flights. Afternoon was lowest at 65.8% across 518 flights.

Departure windowFlightsOn time30+ minCancelled
Early morning48286.1%6.4%2.9%
Late morning13686.0%10.3%2.2%
Afternoon51865.8%18.5%2.3%
Evening35066.6%16.9%5.4%

Which weekday was most reliable for PWM to ORD?

Among qualifying PWM-to-ORD weekday results, Friday had the highest on-time rate: 80.6% of 217 flights. Monday was lowest at 69.6% across 217 flights.

DayFlightsOn time30+ minCancelled
Monday21769.6%14.7%7.4%
Tuesday20673.8%14.1%1.5%
Wednesday19972.9%16.6%1.0%
Thursday21672.2%13.9%3.7%
Friday21780.6%10.1%2.3%
Saturday21574.9%14.9%3.3%
Sunday21676.9%10.2%3.2%

Which airline was most reliable for PWM to ORD?

Among qualifying PWM-to-ORD airline results, Republic Airways had the highest on-time rate: 79.2% of 558 flights. SkyWest Airlines was lowest at 62.3% across 300 flights.

AirlineFlightsOn time30+ minCancelled
Republic Airways55879.2%10.4%3.4%
United Airlines42874.8%13.6%2.1%
SkyWest Airlines30062.3%20.3%4.0%
Envoy Air20078.5%11.5%4.0%

Which month was most reliable for PWM to ORD?

Among qualifying PWM-to-ORD month results, May 2026 had the highest on-time rate: 88.0% of 166 flights. January 2026 was lowest at 55.6% across 36 flights.

MonthFlightsOn time30+ minCancelled
July 202514767.3%24.5%1.4%
August 202517775.7%12.4%2.8%
September 202516575.8%10.3%1.2%
October 202516671.1%12.7%0.0%
November 20259161.5%23.1%8.8%
December 20256275.8%17.7%1.6%
January 20263655.6%27.8%5.6%
February 20266180.3%4.9%6.6%
March 202611666.4%17.2%5.2%
April 202614979.2%7.4%6.0%
May 202616688.0%6.6%0.6%
June 202615078.0%11.3%5.3%

What drove PWM to ORD delay minutes?

National airspace was the largest recorded PWM-to-ORD delay category, accounting for 38.5% of 29,270 BTS-attributed delay minutes during July 2025–June 2026.

Airline34.7%
Late aircraft18.2%
National airspace38.5%
Weather8.4%
Security0.1%
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.