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DelayAtlas

Airport month record

MDWAUG

Chicago Midway International in August 2025

Departures
6,731
Month
August 2025
National, same month
77.4%
Carriers
5
B+GRADE

Historical statistics for August 2025, not live status or a forecast for this year’s August. For today’s conditions at MDW, see live FAA status.

MDW in August lands a B+, level with the national rate of 77.4%. Roughly one flight in five arrives 15 minutes late or worse, and those flights are late by about an hour on average. That is a workable record, not a spotless one. That rests on 6,731 flights, with a median arrival 3 minutes early.

Key figures

On time

77.8%

Arrivals under 15 minutes late, of 6,653 completed departures

Avg delay

58 min

Across delayed arrivals only, not all flights

Cancelled

0.74%

Nationally in August: 1.08%

Whole year

75.1%

MDW across all twelve months

These figures cover 6,731 departures from Chicago Midway International in August 2025. On time means an arrival less than 15 minutes after the scheduled gate time, the DOT's threshold, and the national comparison uses every US departure in the same month rather than the whole year.

Against the year

August next to MDW's other months

Against MDW's own year, August ran 3 points better than the twelve-month rate of 75.1%, which makes it number six of twelve months, best first. Cancellations were unusually low for MDW in August, at 0.74% against 1.49% across the year. Either side of it, July ran 67.2% on time and September 84.1%, so a trip moved by a few weeks would have landed in a worse stretch.

MDW month by month
MonthFlightsOn timeAvg delayCancelledGrade
July 20257,53167.2%69 min1.81%C
August 2025 (this page)6,73177.8%58 min0.74%B+
September 20256,45984.1%46 min0.06%B+
October 20256,53680.2%45 min0.17%B+
November 20255,62080.6%59 min4.96%B−
December 20255,73869.7%57 min0.45%C+
January 20264,84880.9%50 min2.15%B
February 20264,53781.6%46 min0.90%B+
March 20266,50868.7%67 min3.89%C−
April 20266,28277.6%52 min1.18%B
May 20266,26974.0%53 min0.35%C+
June 20266,93764.2%60 min1.53%D

Departure window

The best time of day to leave MDW in August

Departure time matters more here than the choice of carrier. The gap between the best and worst window is 26 points, against half a point between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.

  • 5am–8am726 flights92.1%
  • 8am–11am1,699 flights85.9%
  • 11am–2pm1,141 flights80.5%
  • 2pm–5pm1,078 flights72.2%
  • 5pm–8pm1,181 flights68.2%
  • 8pm–5am906 flights66.6%

Scale runs 60% to 100%. Rows with fewer than 30 flights show a dash.

Book the early departure. Flights leaving between 5am–8am arrive on time 92.1% of the time, against 66.6% for the overnight window. That is 26 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 8am–11am window is the busiest, with 1,699 flights scheduled in it.

Across the week, Wednesday is the strongest day at 84.0% on time and Sunday the weakest at 73.7%. 10 points is a smaller lever than departure hour, but it is free.

On-time rate by day of the week74.9Mon78.4Tue84.0Wed81.0Thu75.6Fri79.3Sat73.7Sun
Monday: 74.9 percent on time. Tuesday: 78.4 percent on time. Wednesday: 84.0 percent on time. Thursday: 81.0 percent on time. Friday: 75.6 percent on time. Saturday: 79.3 percent on time. Sunday: 73.7 percent on time

Carrier by carrier

Which airlines ran best at MDW in August

Only one carrier clears this site's 365-flight floor here, so there is no comparison to draw. The table below is the full picture.

Carriers at MDW in August 2025
AirlineFlightsOn timeAvg delayCancelledGrade
Southwest Airlines6,24877.5%56 min0.70%B+
Frontier Airlinesthin sample16584.2%69 min1.82%B
SkyWest Airlinesthin sample15876.3%63 min1.27%B
Delta Air Linesthin sample12187.5%71 min0.83%A+
Allegiant Airthin sample3976.9%309 min0.00%B+

Route by route

Busiest routes out of MDW in August

Routes from MDW in August 2025
RouteFlightsOn timeAvg delayCancelledGrade
MDW to ATL · Atlantathin sample30580.7%58 min1.31%B
MDW to MSP · Minneapolisthin sample23774.2%64 min0.42%C+
MDW to MCO · Orlandothin sample22771.7%59 min0.44%C+
MDW to DEN · Denverthin sample22673.9%62 min0.44%C+
MDW to LAS · Las Vegasthin sample21583.3%58 min0.00%B+
MDW to PHX · Phoenixthin sample21384.2%55 min1.41%B
MDW to LGA · New Yorkthin sample20274.5%63 min0.99%C+
MDW to DAL · Dallasthin sample19379.6%64 min0.52%B+
MDW to MCI · Kansas Citythin sample18978.8%63 min0.00%B+
MDW to BWI · Baltimorethin sample18477.3%54 min1.63%B
MDW to DCA · Washingtonthin sample18176.0%54 min0.55%B+
MDW to BNA · Nashvillethin sample16877.2%51 min0.60%B+
MDW to HOU · Houstonthin sample16674.5%46 min0.00%C+
MDW to DTW · Detroitthin sample15976.3%65 min1.89%B
MDW to PHL · Philadelphiathin sample15576.5%58 min0.65%B+
MDW to STL · St. Louisthin sample15484.3%63 min0.65%B+
MDW to BOS · Bostonthin sample13473.9%59 min0.00%C+
MDW to TPA · Tampathin sample12979.8%47 min0.78%B+
MDW to OMA · Omahathin sample12582.3%73 min0.80%B+
MDW to LAX · Los Angelesthin sample12175.2%61 min0.00%B+
MDW to CMH · Columbusthin sample11983.2%72 min0.00%B+
MDW to PIT · Pittsburghthin sample11280.9%52 min1.79%B
MDW to CLE · Clevelandthin sample10878.5%57 min0.93%B+
MDW to AUS · Austinthin sample10782.2%49 min0.00%B+
MDW to RDU · Raleighthin sample9381.5%60 min1.08%B

Delay causes

What held MDW up in August

One category carries most of the weight here. Late-arriving aircraft accounts for 44% of the 86,000 delay minutes carriers reported, and the remaining four split what is left. The split is by minutes rather than by flights, so a few very long delays count for as much as many short ones.

  • Late-arriving aircraft
    44%
  • Carrier
    31%
  • National Airspace System
    17%
  • Extreme weather
    7%
  • Security
    1%

44% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. That is a cascade, and cascades start small and grow through the day. Across 86,000 reported delay minutes here, that single category outweighs weather by 7 to one. It is the strongest argument for booking the first departure of the morning, when the aircraft has been sitting at the gate overnight with nothing to inherit. The split is drawn from 85,754 reported delay minutes.

Cancellations are rare at 0.74%, below the national 1.08% and low enough to earn the plus on the grade. Roughly one flight in 100 is called off; the risk here is arriving late, not not arriving.

6.2% of arrivals land an hour or more late, close to the national 8.2%. That is the figure that decides a connection, and it says a 60 to 75 minute layover is reasonable here while anything under 45 minutes is a bet. Most delays on this route last about an hour, which a normal layover absorbs.

What to do with this

Flying from MDW in August

For a August trip through MDW: expect 77.8% on time and 0.74% cancelled, going by August 2025. The 5am–8am window was the strongest part of the day.

Related

Where to go next

Source: US DOT Bureau of Transportation Statistics, on-time performance data, July 2025 to June 2026. Last updated 15 September 2026; recomputed monthly. How this data is collected.