Today: UA 512 at 07:40 is the safest bet, 7% chance of being 15+ min late; evening flights run 17–31%.

Safest bet today UA 512 IAH 07:40 → DCA 11:39 · 7% chance 15+ min late · usually 95% on time Riskiest AA 5333 IAH 17:00 → DCA 21:16 · 31% chance 15+ min late · usually 38% on time

Against a calm day 18% average chance a nonstop arrives 15+ min late; 21% for the same flights on a calm-weather day

Every nonstop today

12-month record →

Ranked by the chance of arriving 15+ minutes late, with each flight’s on-time record over Aug 2025 – Jul 2026 beside it. Times are local. Pick a flight for its forecast. Click a column to sort.


UA 512 United Flight history →	IAH 07:40	DCA 11:39	7%	3%	0.2%	95%
AA 5247 American flown by PSA Flight history →	IAH 06:43	DCA 10:59	7%	5%	0.8%	94%
UA 2047 United Flight history →	IAH 07:46	DCA 11:56	8%	3%	0.2%	97%
OH 5410 PSA	IAH 07:04	DCA 11:02	12%	7%	0.9%	no record
UA 654 United Flight history →	IAH 11:55	DCA 16:03	15%	6%	0.2%	75%
UA 235 United	IAH 16:49	DCA 20:54	17%	8%	0.3%	no record
UA 625 United Flight history →	IAH 14:20	DCA 18:31	17%	7%	0.3%	69%
OH 5252 PSA	IAH 10:44	DCA 15:01	19%	8%	0.8%	no record
AA 5526 American flown by PSA Flight history →	IAH 10:48	DCA 15:03	21%	8%	0.8%	62%
UA 2224 United Flight history →	IAH 19:50	DCA 23:59	22%	7%	0.7%	70%
UA 1627 United Flight history →	IAH 18:05	DCA 22:15	25%	9%	0.7%	66%
OH 5458 PSA	IAH 17:21	DCA 21:18	28%	11%	0.8%	no record
AA 5333 American flown by PSA Flight history →	IAH 17:00	DCA 21:16	31%	11%	0.8%	38%

How these are worked out. Each flight’s odds are our forecast for that day; flights of airlines we don’t forecast yet use their 12-month record and are marked. Makes the connection: the first flight’s 12-month lateness curve, scaled so its chance of arriving 15+ min late matches the day’s forecast, at the layover minus the 45-minute minimum (90 on separate tickets). Arrives on time: first flight not cancelled × connection made × second flight not cancelled × second flight within 15 minutes, each from the day’s forecast.

About this data: forecast odds from our model for Mon, Oct 5 (newest published update); 12-month records from US DOT on-time data, Aug 2025 – Jul 2026, all US airlines; regional flights count under the airline that sells them. JSON