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

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

72.1% of 1,486 official scheduled ORD-to-PWM flights arrived on time; 17.6% arrived at least 30 minutes late and 2.5% 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
72.1%arrived on time
17.6%30+ min late
2.5%cancelled
1,486scheduled flights
Based on July 2025–June 2026; on time means arrival less than 15 minutes late.
60+ minutes late9.2%all scheduled flights
120+ minutes late3.9%all scheduled flights
Diverted0.1%did not reach as scheduled
Average arrival+10.4 mincompleted flights

Which departure time was most reliable for ORD to PWM?

Among qualifying ORD-to-PWM departure window results, Early morning had the highest on-time rate: 89.6% of 183 flights. Evening was lowest at 60.2% across 561 flights.

Departure windowFlightsOn time30+ minCancelled
Early morning18389.6%4.4%0.5%
Late morning43775.1%16.0%1.1%
Afternoon30278.8%14.2%2.3%
Evening56160.2%25.1%4.3%

Which weekday was most reliable for ORD to PWM?

Among qualifying ORD-to-PWM weekday results, Friday had the highest on-time rate: 76.5% of 217 flights. Monday was lowest at 68.1% across 216 flights.

DayFlightsOn time30+ minCancelled
Monday21668.1%19.9%5.1%
Tuesday20675.7%17.0%0.5%
Wednesday19970.4%22.1%1.5%
Thursday21773.7%15.2%2.8%
Friday21776.5%11.1%1.8%
Saturday21469.6%19.2%1.9%
Sunday21770.5%19.4%3.7%

Which airline was most reliable for ORD to PWM?

Among qualifying ORD-to-PWM airline results, Envoy Air had the highest on-time rate: 79.4% of 199 flights. SkyWest Airlines was lowest at 67.3% across 300 flights.

AirlineFlightsOn time30+ minCancelled
Republic Airways55873.5%16.1%2.9%
United Airlines42970.2%19.6%1.2%
SkyWest Airlines30067.3%20.7%3.0%
Envoy Air19979.4%13.1%3.5%

Which month was most reliable for ORD to PWM?

Among qualifying ORD-to-PWM month results, February 2026 had the highest on-time rate: 80.6% of 62 flights. January 2026 was lowest at 57.1% across 35 flights.

MonthFlightsOn time30+ minCancelled
July 202514765.3%25.9%1.4%
August 202517771.2%16.4%2.8%
September 202516579.4%9.7%0.0%
October 202516675.3%15.1%0.0%
November 20259068.9%16.7%5.6%
December 20256259.7%30.6%1.6%
January 20263557.1%25.7%5.7%
February 20266280.6%8.1%6.5%
March 202611761.5%25.6%4.3%
April 202614973.2%16.8%4.0%
May 202616680.1%15.1%0.6%
June 202615073.3%17.3%4.0%

What drove ORD to PWM delay minutes?

Late aircraft was the largest recorded ORD-to-PWM delay category, accounting for 44.0% of 26,207 BTS-attributed delay minutes during July 2025–June 2026.

Airline31.5%
Late aircraft44.0%
National airspace17.5%
Weather7.0%
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.