{"chart":{"slug":"causes-of-flight-delays","title":"What causes most flight delays?","takeaway":"In the 12 months through August 2026, 39.8% of all minutes of delay came from a late-arriving aircraft: a plane that left its last airport late. The airline itself (crew, maintenance, cleaning, fueling) caused 32.9%, the air traffic system 21.1% and severe weather 6%. Weather also hides in the other causes: BTS counts ordinary weather that slows traffic under the air traffic system.","topic":"Air travel","chart_type":"bar","ranking":false,"x_label":"Cause of delay","y_label":"% of all minutes of delay","unit":"percent","points_count":5,"source":{"name":"U.S. Bureau of Transportation Statistics, Airline On-Time Performance (Reporting Carrier On-Time Performance, 1987–present)","url":"https://www.transtats.bts.gov/DL_SelectFields.aspx?gnoyr_VQ=FGJ\u0026QO_fu146_anzr=b0-gvzr"},"license":{"name":"Public domain (U.S. government work)","url":"https://www.usa.gov/government-copyright"},"data_as_of":"2026-08-31","updated_at":"2026-10-20T16:40:18.961Z","url":"https://chart.ly/charts/causes-of-flight-delays","api_url":"https://chart.ly/api/v1/charts/causes-of-flight-delays","csv_url":"https://chart.ly/charts/causes-of-flight-delays/data.csv","image_url":"https://chart.ly/charts/causes-of-flight-delays/image.png","embed_url":"https://chart.ly/charts/causes-of-flight-delays/embed","credit":"U.S. Bureau of Transportation Statistics, Airline On-Time Performance (Reporting Carrier On-Time Performance, 1987–present), via Chartly (https://chart.ly/charts/causes-of-flight-delays)","credit_html":"U.S. Bureau of Transportation Statistics, Airline On-Time Performance (Reporting Carrier On-Time Performance, 1987–present), via \u003ca href=\"https://chart.ly/charts/causes-of-flight-delays\"\u003eChartly\u003c/a\u003e","average_label":null,"zero_axis":true,"data":[{"label":"Late-arriving aircraft","value":39.8},{"label":"The airline (crew, maintenance, cleaning, fueling)","value":32.9},{"label":"Air traffic system (congestion, airport, ordinary weather)","value":21.1},{"label":"Severe weather","value":6.0},{"label":"Security","value":0.1}],"annotations":[]},"docs":"https://chart.ly/developers","terms":"Free to use with credit: wherever you show or quote a chart's data, name Chartly with a link to that chart's url (each chart's credit line does both) and credit its source as its license asks.","credit":"U.S. Bureau of Transportation Statistics, Airline On-Time Performance (Reporting Carrier On-Time Performance, 1987–present), via Chartly (https://chart.ly/charts/causes-of-flight-delays)"}