Route on-time record

SEA to SLC: most on-time flights and the best time to fly

Seattle (Seattle–Tacoma International Airport) to Salt Lake City (Salt Lake City International Airport). 4,119 nonstop flights in Jun 2025 to May 2026, 83% arrived within 15 minutes and 1.0% were cancelled. The most reliable flight number was Delta 2858 at 7:15 AM.

Flying on a specific date? We’ll adjust for the month, the weekday and the forecast.

SEA → SLC

Seattle to Salt Lake City: 4,119 nonstop flights a year

On time (12 months)

83%

Cancelled

1.0%

avg delay 10 min

Best time to leave

Before 9 AM

93% on time vs 78% 3 to 6 PM

Most reliable airline

Delta

86% chance on time

Check SEA to SLC fares

Lowest nonstop fare seen in the next two months: $251 (Alaska 430 on 2026-10-26). 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 · Delta 2858
7:15 AM → 10:31 AM2h 16m nonstop
Local times, typical schedule. Last flown 2026-05-31.
95%
chance on time
On time (history)
100%
Cancelled
4.0%
Avg arrival delay
0 min
- Arrived on time 100% of the time (24 flights, Jun 2025 to May 2026).
- Leaves in this route's most on-time window (Before 9 AM: 93% on time; 3 to 6 PM: 78%).
- Departs outside SEA's trouble window (4 PM to 10 PM, when 54% of its 68 ground stops and delay programs started).
- Short track record (24 flights), so its score leans on the airline's record at this hour.
Limited track record · 24 flights
Find Delta 2858 fares Opens this date on Aviasales
#2 · Delta 1128
5:30 AM → 8:31 AM2h 05m nonstop
Local times, typical schedule. Last flown 2026-05-31.
93%
chance on time
On time (history)
93%
Cancelled
0.3%
Avg arrival delay
7 min
- Arrived on time 93% of the time (364 flights, Jun 2025 to May 2026).
- Leaves in this route's most on-time window (Before 9 AM: 93% on time; 3 to 6 PM: 78%).
- Departs outside SEA's trouble window (4 PM to 10 PM, when 54% of its 68 ground stops and delay programs started).
Strong track record · 364 flights
Find Delta 1128 fares Opens this date on Aviasales
#3 · Alaska 430
7:05 AM → 10:12 AM2h 07m nonstop
Local times, typical schedule. Last flown 2026-05-31.
91%
chance on time
On time (history)
93%
Cancelled
2.1%
Avg arrival delay
4 min
- Arrived on time 93% of the time (227 flights, Jun 2025 to May 2026).
- Leaves in this route's most on-time window (Before 9 AM: 93% on time; 3 to 6 PM: 78%).
- Departs outside SEA's trouble window (4 PM to 10 PM, when 54% of its 68 ground stops and delay programs started).
Strong track record · 227 flights
Find Alaska 430 fares Opens this date on Aviasales
#4 · Delta 1016
9:25 AM → 12:28 PM2h 09m nonstop
Local times, typical schedule. Last flown 2026-05-31.
89%
chance on time
On time (history)
90%
Cancelled
0.8%
Avg arrival delay
6 min
- Arrived on time 90% of the time (359 flights, Jun 2025 to May 2026).
- Departs outside SEA's trouble window (4 PM to 10 PM, when 54% of its 68 ground stops and delay programs started).
Strong track record · 359 flights
Find Delta 1016 fares Opens this date on Aviasales
#5 · Delta 1265
11:25 AM → 2:26 PM2h 05m nonstop
Local times, typical schedule. Last flown 2026-05-31.
84%
chance on time
On time (history)
85%
Cancelled
0.9%
Avg arrival delay
11 min
- Arrived on time 85% of the time (341 flights, Jun 2025 to May 2026).
- Departs outside SEA's trouble window (4 PM to 10 PM, when 54% of its 68 ground stops and delay programs started).
Strong track record · 341 flights
Find Delta 1265 fares Opens this date on Aviasales
#6 · Delta 1239
7:35 PM → 10:43 PM2h 08m nonstop
Local times, typical schedule. Last flown 2026-05-31.
83%
chance on time
On time (history)
84%
Cancelled
0.4%
Avg arrival delay
10 min
- Arrived on time 84% of the time (243 flights, Jun 2025 to May 2026).
- Departs inside SEA's trouble window: 54% of its 68 ground stops and delay programs started between 4 PM and 10 PM.
Strong track record · 243 flights
Find Delta 1239 fares Opens this date on Aviasales
#7 · Delta 1120
1:32 PM → 4:40 PM2h 10m nonstop
Local times, typical schedule. Last flown 2026-05-31.
83%
chance on time
On time (history)
83%
Cancelled
0.5%
Avg arrival delay
11 min
- Arrived on time 83% of the time (362 flights, Jun 2025 to May 2026).
- Departs outside SEA's trouble window (4 PM to 10 PM, when 54% of its 68 ground stops and delay programs started).
Strong track record · 362 flights
Find Delta 1120 fares Opens this date on Aviasales
#8 · Delta 1165
4:55 PM → 7:55 PM2h 04m nonstop
Local times, typical schedule. Last flown 2026-05-31.
80%
chance on time
On time (history)
80%
Cancelled
0.7%
Avg arrival delay
12 min
- Arrived on time 80% of the time (300 flights, Jun 2025 to May 2026).
- Leaves in this route's least on-time window (3 to 6 PM: 78% on time; Before 9 AM: 93%).
- Departs inside SEA's trouble window: 54% of its 68 ground stops and delay programs started between 4 PM and 10 PM.
Strong track record · 300 flights
Find Delta 1165 fares Opens this date on Aviasales
#9 · SkyWest 3298 · sold as United Express, Delta Connection, American Eagle or Alaska
6:59 PM → 10:05 PM2h 10m nonstop
Local times, typical schedule. Last flown 2026-05-31.
79%
chance on time
On time (history)
80%
Cancelled
0.0%
Avg arrival delay
11 min
- Arrived on time 80% of the time (293 flights, Jun 2025 to May 2026).
- Never cancelled in 293 scheduled flights.
- Departs inside SEA's trouble window: 54% of its 68 ground stops and delay programs started between 4 PM and 10 PM.
- 69% of its delay minutes came from the plane arriving late from an earlier flight.
Strong track record · 293 flights
Find 6:59 PM flight fares Opens this date on Aviasales
#10 · Alaska 669
4:42 PM → 7:46 PM2h 04m nonstop
Local times, typical schedule. Last flown 2026-05-12.
79%
chance on time
On time (history)
85%
Cancelled
0.0%
Avg arrival delay
7 min
- Arrived on time 85% of the time (104 flights, Jun 2025 to May 2026).
- Never cancelled in 104 scheduled flights.
- Leaves in this route's least on-time window (3 to 6 PM: 78% on time; Before 9 AM: 93%).
- Departs inside SEA's trouble window: 54% of its 68 ground stops and delay programs started between 4 PM and 10 PM.
Moderate track record · 104 flights
Find Alaska 669 fares Opens this date on Aviasales

Airlines on this route

Season-adjusted chance of operating and arriving on time.

Delta Air Lines86%
2,218 flights · 87% on time as flown · 0.6% cancel
SkyWest Airlines (sold as United Express, Delta Connection, American Eagle or Alaska)81%
439 flights · 80% on time as flown · 0.2% cancel
Alaska Airlines77%
1,355 flights · 78% on time as flown · 1.7% cancel
Frontier Airlines74%
107 flights · 70% on time as flown · 1.7% cancel

On time by departure time

All airlines, scheduled local departure, Jun 2025 to May 2026.

Before 9 AM93%
814 flights · avg delay 6 min
9 AM to noon81%
1,139 flights · avg delay 10 min
Noon to 3 PM83%
493 flights · avg delay 10 min
3 to 6 PM78%
841 flights · avg delay 12 min
6 to 9 PM81%
831 flights · avg delay 10 min

Best day: Wednesday (86%). Worst: Friday (81%).

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)48%
Late-arriving aircraft39%
Air traffic control and airport volume12%
Severe weather2%

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

SEA to SLC questions

What time of day is best to fly SEA to SLC?: Before 9 AM: 93% of flights arrived on time, against 78% for departures 3 to 6 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 SEA to SLC?: Delta, with a season-adjusted 86% chance of operating and arriving on time over 2,218 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 SEA to SLC?: July (78% on time); the best was April (88%), 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.

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