IAH→JAX

Book the early departure. Flights leaving between 5am–8am arrive on time 89.9% of the time, against 56.8% for the afternoon window. That is 33 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 11am–2pm window is the busiest, with 237 flights scheduled in it.

July is the worst month at 50.9% on time, 42 points below January, the best at 93.3%. Summer afternoon convection and peak-season schedules land on the same weeks every year, so this is a pattern you can book around rather than a run of bad luck. November was the busiest month here, with 88 flights.

Across the week, Tuesday is the strongest day at 85.6% on time and Sunday the weakest at 65.7%. 20 points is a smaller lever than departure hour, but it is free.

Extreme weather accounts for 14% of delay minutes, well above the single-digit share typical across the system. Weather delays are lumpy: they arrive as whole bad days rather than as a steady drag, so the monthly strip above is the more useful view of the risk. The national share is 6%, so this operation carries roughly 2.3 times the usual weather exposure. The split is drawn from 11,064 reported delay minutes.

45% 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 11,000 reported delay minutes here, that single category outweighs weather by 3 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.

Cancellations are rare at 0.42%, below the national 1.81% 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.