Route profile
ATL→IAH
Flight reliability, delays and best times to fly from Atlanta to Houston. · 689 miles
Right now
Current conditions at both ends of this route.
Aviation weather is not currently a factor.
Aviation weather is not currently a factor.
Airport conditions describe the airfield, not any individual flight. An airport operating normally is not a guarantee that a specific flight will depart on time.
Route reliability
July 2023 – June 2026
Better than 27% of comparable major US routes (4,577 compared)
Calculated from 13,939 flights. How this is calculated
Source: US DOT Bureau of Transportation Statistics · Data covering July 2023 – June 2026
Best time to fly
On-time arrival rate by scheduled local departure time.
ATL → IAH flights departing 5–9 AM arrived on time 83.9% of the time, against 67.8% for 6–9 PM departures — a gap of 16.1 percentage points.
By departure window
By departure hour
Source: FlyerIntel analysis of US DOT BTS data · July 2023 – June 2026 · Buckets with fewer than 120 flights are not scored.
Airlines on this route
Performance by the carrier that actually operated the flight.
| Carrier | Flights | On time | Cancelled | Median delay | Severe |
|---|---|---|---|---|---|
| Delta Air Lines | 7,119 | 76.6% | 1.49% | -2 min | 7.0% |
| United Airlines | 3,390 | 81.4% | 1.30% | -7 min | 7.2% |
| Spirit Airlines | 1,669 | 67.0% | 2.70% | 0 min | 13.3% |
| Frontier Airlines | 1,635 | 68.3% | 2.14% | -2 min | 15.4% |
United Airlines arrived on time 14.4 percentage points more often than Spirit Airlines on this route.
Source: FlyerIntel analysis of US DOT BTS data · July 2023 – June 2026 · Carriers with fewer than 200 flights on this route are not listed.
Other ways to fly Atlanta to Houston
Airport pairs serving the same journey, grouped by the DOT's own city-market definition. They do not perform the same way.
| Route | Flights | On time | Cancelled | Median delay | Score |
|---|---|---|---|---|---|
| ATL→IAH this route Atlanta to Houston | 13,939 | 75.7% | 1.65% | -3 min | 57 |
| ATL→HOU Atlanta to Houston | 9,381 | 81.0% | 1.00% | -6 min | 73 |
ATL → HOU is the most reliable pairing for this journey at 81.0% on time, against 75.7% for ATL → IAH.
Source: FlyerIntel analysis of US DOT BTS data · July 2023 – June 2026 · Grouped by DOT city market, which places Newark with the New York airports and Baltimore with the Washington ones.
Individual flights on this route
The same route is not equally reliable at every hour. These are the flight numbers with enough operating history to judge separately.
| Flight | Scheduled | Operations | On time |
|---|---|---|---|
| DL1601 Delta Air Lines | 10:40 PM | 1,088 | 72.0% |
| DL1284 Delta Air Lines | 7:59 PM | 967 | 72.2% |
| DL1682 Delta Air Lines | 10:00 AM | 960 | 82.8% |
| DL1585 Delta Air Lines | 7:05 AM | 912 | 85.0% |
| DL1572 Delta Air Lines | 1:45 PM | 838 | 80.2% |
| DL1223 Delta Air Lines | 4:25 PM | 716 | 74.3% |
| F91403 Frontier Airlines | 6:00 AM | 681 | 75.7% |
| F94075 Frontier Airlines | 9:15 PM | 429 | 60.7% |
| DL1131 Delta Air Lines | 5:00 PM | 410 | 65.8% |
| F92399 Frontier Airlines | 8:45 AM | 400 | 64.7% |
Source: FlyerIntel analysis of US DOT BTS data · July 2023 – June 2026 · Flight numbers with fewer than 270 operations on this route, or no longer scheduled, are not listed.
Weekly and seasonal patterns
By day of week
Wednesday is historically the most reliable day and Sunday the least, a gap of 5.9 percentage points.
By month
July is historically the weakest month and October the strongest, a spread of 20.9 percentage points.
Historical trend
On-time arrival rate by month.
Over the most recent 12 months (2025-07 to 2026-06), on-time arrivals averaged 76.4% against 73.2% in the 12 months before — improving by 3.2 percentage points.
Source: FlyerIntel analysis of US DOT BTS data · July 2023 – June 2026
Data and methodology
All figures on this page are calculated by FlyerIntel from 13,939 ATL → IAH flight records published by the US DOT Bureau of Transportation Statistics, covering July 2023 – June 2026. A flight is counted as delayed when it arrives 15 or more minutes after its scheduled arrival time, following BTS methodology. Cancelled and diverted flights have no arrival time and are excluded from on-time rates rather than counted as late.