Route on-time record
ATL to IAH: most on-time flights and the best time to fly
Atlanta (Hartsfield Jackson Atlanta International Airport) to Houston (George Bush Intercontinental Airport). 4,908 nonstop flights in Jun 2025 to May 2026, 75% arrived within 15 minutes and 2.0% were cancelled. The most reliable flight number was United 425 at 11:44 AM.
Flying on a specific date? We’ll adjust for the month, the weekday and the forecast.
ATL → IAH
Atlanta to Houston: 4,908 nonstop flights a year
On time (12 months)
75%
Cancelled
2.0%
avg delay 18 min
Best time to leave
Before 9 AM
83% on time vs 67% after 9 PM
Most reliable airline
United
83% chance on time
Lowest nonstop fare seen in the next two months: $31 (Frontier 2399 on 2026-10-28). Fares open on our travel partner (Aviasales). Pick the flight number you chose here.
Most reliable nonstop flights
Ranked by the chance the flight operates and arrives within 15 minutes of schedule, from Jun 2025 to May 2026 records.
#1 · United 425
11:44 AM → 1:13 PM2h 29m nonstop
Local times, typical schedule. Last flown 2026-05-30.
89%
chance on time
- On time (history)
- 90%
- Cancelled
- 0.0%
- Avg arrival delay
- 9 min
- Arrived on time 90% of the time (102 flights, Jun 2025 to May 2026).
- Never cancelled in 102 scheduled flights.
- Departs outside ATL's trouble window (1 PM to 7 PM, when 59% of its 96 ground stops and delay programs started).
- Lands inside IAH's trouble window: 60% of its 92 ground stops and delay programs started between noon and 6 PM.
Moderate track record · 102 flights
Find United 425 fares Opens this date on Aviasales#2 · United 1687
9:10 AM → 10:39 AM2h 29m nonstop
Local times, typical schedule. Last flown 2026-05-20. Same departure also flew as United 1012, 213; its record covers all of them.
87%
chance on time
- On time (history)
- 89%
- Cancelled
- 3.0%
- Avg arrival delay
- 8 min
- Arrived on time 89% of the time (65 flights, Jun 2025 to May 2026).
- Departs outside ATL's trouble window (1 PM to 7 PM, when 59% of its 96 ground stops and delay programs started).
Moderate track record · 65 flights
Find United 1687 fares Opens this date on Aviasales#3 · United 532
7:00 AM → 8:21 AM2h 21m nonstop
Local times, typical schedule. Last flown 2026-05-31.
85%
chance on time
- On time (history)
- 87%
- Cancelled
- 0.7%
- Avg arrival delay
- 10 min
- Arrived on time 87% of the time (144 flights, Jun 2025 to May 2026).
- Leaves in this route's most on-time window (Before 9 AM: 83% on time; After 9 PM: 67%).
- Departs outside ATL's trouble window (1 PM to 7 PM, when 59% of its 96 ground stops and delay programs started).
Moderate track record · 144 flights
Find United 532 fares Opens this date on Aviasales#4 · Delta 1988
12:35 PM → 1:54 PM2h 19m nonstop
Local times, typical schedule. Last flown 2026-04-12.
83%
chance on time
- On time (history)
- 90%
- Cancelled
- 3.2%
- Avg arrival delay
- 12 min
- Arrived on time 90% of the time (30 flights, Jun 2025 to May 2026).
- Cancelled 3.2% of the time (1 of 31).
- Departs outside ATL's trouble window (1 PM to 7 PM, when 59% of its 96 ground stops and delay programs started).
- Lands inside IAH's trouble window: 60% of its 92 ground stops and delay programs started between noon and 6 PM.
Limited track record · 30 flights
Find Delta 1988 fares Opens this date on Aviasales#5 · United 1359
7:04 PM → 8:33 PM2h 29m nonstop
Local times, typical schedule. Last flown 2026-05-20.
82%
chance on time
- On time (history)
- 83%
- Cancelled
- 1.5%
- Avg arrival delay
- 11 min
- Arrived on time 83% of the time (65 flights, Jun 2025 to May 2026).
- Departs outside ATL's trouble window (1 PM to 7 PM, when 59% of its 96 ground stops and delay programs started).
Moderate track record · 65 flights
Find United 1359 fares Opens this date on Aviasales#6 · United 521
3:57 PM → 5:25 PM2h 28m nonstop
Local times, typical schedule. Last flown 2026-05-20.
81%
chance on time
- On time (history)
- 83%
- Cancelled
- 0.0%
- Avg arrival delay
- 18 min
- Arrived on time 83% of the time (87 flights, Jun 2025 to May 2026).
- Never cancelled in 87 scheduled flights.
- Departs inside ATL's trouble window: 59% of its 96 ground stops and delay programs started between 1 PM and 7 PM.
- Lands inside IAH's trouble window: 60% of its 92 ground stops and delay programs started between noon and 6 PM.
Moderate track record · 87 flights
Find United 521 fares Opens this date on Aviasales#7 · Delta 1585
7:30 AM → 8:44 AM2h 17m nonstop
Local times, typical schedule. Last flown 2026-05-31.
80%
chance on time
- On time (history)
- 82%
- Cancelled
- 3.1%
- Avg arrival delay
- 9 min
- Arrived on time 82% of the time (313 flights, Jun 2025 to May 2026).
- Cancelled 3.1% of the time (10 of 325).
- Leaves in this route's most on-time window (Before 9 AM: 83% on time; After 9 PM: 67%).
- Departs outside ATL's trouble window (1 PM to 7 PM, when 59% of its 96 ground stops and delay programs started).
Strong track record · 313 flights
Find Delta 1585 fares Opens this date on Aviasales#8 · Delta 1682
9:51 AM → 11:09 AM2h 18m nonstop
Local times, typical schedule. Last flown 2026-05-31.
80%
chance on time
- On time (history)
- 81%
- Cancelled
- 2.1%
- Avg arrival delay
- 12 min
- Arrived on time 81% of the time (333 flights, Jun 2025 to May 2026).
- Departs outside ATL's trouble window (1 PM to 7 PM, when 59% of its 96 ground stops and delay programs started).
Strong track record · 333 flights
Find Delta 1682 fares Opens this date on Aviasales#9 · Delta 1223
2:30 PM → 3:44 PM2h 15m nonstop
Local times, typical schedule. Last flown 2026-05-31. Same departure also flew as Delta 2709; its record covers all of them.
79%
chance on time
- On time (history)
- 81%
- Cancelled
- 1.4%
- Avg arrival delay
- 12 min
- Arrived on time 81% of the time (349 flights, Jun 2025 to May 2026).
- Departs inside ATL's trouble window: 59% of its 96 ground stops and delay programs started between 1 PM and 7 PM.
- Lands inside IAH's trouble window: 60% of its 92 ground stops and delay programs started between noon and 6 PM.
Strong track record · 349 flights
Find Delta 1223 fares Opens this date on Aviasales#10 · Delta 1148
12:00 PM → 1:14 PM2h 14m nonstop
Local times, typical schedule. Last flown 2026-05-31.
78%
chance on time
- On time (history)
- 72%
- Cancelled
- 0.0%
- Avg arrival delay
- 17 min
- Arrived on time 72% of the time (25 flights, Jun 2025 to May 2026).
- Departs outside ATL's trouble window (1 PM to 7 PM, when 59% of its 96 ground stops and delay programs started).
- Lands inside IAH's trouble window: 60% of its 92 ground stops and delay programs started between noon and 6 PM.
- Short track record (25 flights), so its score leans on the airline's record at this hour.
Limited track record · 25 flights
Find Delta 1148 fares Opens this date on Aviasales
Airlines on this route
Season-adjusted chance of operating and arriving on time.
- United Airlines83%
1,234 flights · 85% on time as flown · 1.3% cancel
- Delta Air Lines74%
2,492 flights · 76% on time as flown · 2.2% cancel
- Frontier Airlines65%
738 flights · 65% on time as flown · 1.4% cancel
- Spirit Airlines63%
444 flights · 64% on time as flown · 3.9% cancel
On time by departure time
All airlines, scheduled local departure, Jun 2025 to May 2026.
- Before 9 AM83%
806 flights · avg delay 11 min
- 9 AM to noon83%
1,047 flights · avg delay 11 min
- Noon to 3 PM78%
633 flights · avg delay 15 min
- 3 to 6 PM69%
928 flights · avg delay 24 min
- 6 to 9 PM71%
748 flights · avg delay 26 min
- After 9 PM67%
746 flights · avg delay 25 min
Best day: Wednesday (78%). Worst: Sunday (72%).
Smarter routing
Nearby airports that run more on time
ATL → HOU 78% chance on time
Hartsfield Jackson Atlanta International Airport to William P. Hobby Airport · 2,953 flights a year · 24 mi from your airports · yours: 74%
On time by month
All airlines, Jun 2023 to May 2026. Several years per month, so one stormy season doesn't define a month. Travel-month estimates use this seasonal pattern.
What delays this route
- Airline (crew, maintenance, boarding)37%
- Late-arriving aircraft34%
- Air traffic control and airport volume26%
- Severe weather3%
Share of delay minutes by the cause airlines report to the US DOT.
Historical odds, not a guarantee. Built from the US DOT Bureau of Transportation Statistics on-time reports (Jun 2025 to May 2026), FAA ground stop and delay program advisories, and 20 years of airport weather observations. Covers US airlines that report to the DOT; schedules are flights operated recently, so confirm times when you book. ATIS Alerts is not affiliated with any airline. Fares are what Aviasales travelers saw in recent searches (USD, one way, 1 adult), not live quotes; the partner site shows the current price. Fare links go to our travel partner and may earn us a commission at no cost to you. Affiliate disclosure
ATL to IAH questions
- What time of day is best to fly ATL to IAH?
- Before 9 AM: 83% of flights arrived on time, against 67% for departures after 9 PM. Later flights inherit delays from earlier ones, so the first departures of the day usually run best.
- Which airline is most on time from ATL to IAH?
- United, with a season-adjusted 83% chance of operating and arriving on time over 1,234 flights. The adjustment compares each airline with what the route did in the months it flew, so a carrier that skipped a stormy month gets no free credit.
- What is the worst month for delays on ATL to IAH?
- July (63% on time); the best was October (84%), averaged over Jun 2023 to May 2026.
- Is this a prediction for my flight?
- No. These are historical odds from the US DOT on-time reports, FAA advisories and airport weather records. Check your flight status and the FAA delay board on the day you fly.
More routes from ATL
- IAH to ATL (return)
- ATL to LGA 73%
- ATL to MCO 69%
- ATL to FLL 69%
- ATL to DCA 69%
- ATL to DFW 73%
- ATL to ORD 71%
- ATL to EWR 72%
- ATL to MIA 70%
- ATL to TPA 71%
- ATL to PHL 73%
- ATL to DEN 76%
- ATL to BWI 74%
Live status: FAA delays and ground stops