DL3987Delta Air Lines · SEA → ONT
live · 41m ago
Route confirmed Delta Air Lines

DL3987 SeattleSEA · 20:11 OntarioONT · 23:00

DL3987 by Delta Air Lines flies from Seattle (SEA) to Ontario (ONT) for the Sat, Nov 14 departure.

Right nowEn route to Ontario
En route

en route from SEA to ONT

En routeDL3987 · position estimated
SEASeattleONTOntario
Estimated from the boards

Board estimate · gate and arrival times.

Typical arrival+115 minmedian over 4 operations
Wins back in air~99 minmedian gate push vs arrival · how planes make up time →

Where the minutes go

last 4 operations · gate push → arrival
0+71+143+214 min
11-14
+206 arrival
11-13
+214 gate · +206 arrival
11-12
+23 arrival
11-11
−14 arrival

The bar is how late it left the gate; the ring is where it actually arrived. Board clocks, not estimates.

The route today

live boards
SEASeattleHigh riskSEA delay board →
ONTOntarioOn-time likelyONT delay board →
SEA→ONTevery carrier, schedules and on-time historyRoute intelligence →

Weather lens

Delay & cancellation outlook for this flight

Measured, 90-day sample
37%Chance of 15+ min delay
1.4%Chance of cancellation
+8 minTypical airport delay in this weather

Conditions at SEA and ONT are near their clear-air norm right now, so this reflects the route's recent baseline rather than a weather penalty. These figures come from both airports' records under conditions like today's, over the last 90 days.

Pro Flight Search tracking, 90 days · the weather × delay correlation study → · live weather risk by airport →

Tomorrow at Seattle

Forecast

Sun 15 Nov, local date

High13°Clikely 12°C to 15°C
Low8°Clikely 7°C to 10°C
  • 97% chance of rain

Forecast: GateWeather · incl. data from ECMWF (CC BY 4.0, modified) · Expected values for tomorrow from a forecast model, kept apart from today's measured figures.

Tomorrow at Ontario

Forecast

Sun 15 Nov, local date

High22°Clikely 20°C to 23°C
Low12°Clikely 10°C to 13°C

Forecast: GateWeather · incl. data from ECMWF (CC BY 4.0, modified) · Expected values for tomorrow from a forecast model, kept apart from today's measured figures.

When it flies

scheduled departures
061422
M
T
W
T
F
S
S

Each mark is a scheduled departure at its origin-local time. Today is highlighted.

Other Seattle to Ontario flights today

same route · Delta Air Lines
DL4070departs 08:25
DL4031departs 14:30

If DL3987 is cancelled, these are the other Delta Air Lines nonstop flights from Seattle to Ontario on the same day, with scheduled departure times in SEA local time. Most flights that show a delay still operate. Rebooking usually helps only when that delay is very large. Every airline on this route →

How DL3987 actually runs

Pro Flight Search has tracked every published board update for DL3987 across the SEA and ONT boards: schedule changes, gate pushes and actual clocks. Usually lands ~121 min late. Based on 4 confirmed landings · 1/4 within 15 min of schedule.

The verdict above is that record speaking, so it reflects how DL3987 operates rather than what the timetable promises. Numbers refresh as new flights operate.

Technical record

How this operation is measured

board clocksaircraft

Board log

scheduled → actual, per operation
11-14SEA 20:11ONT 23:00 02:26 (+206)
11-13SEA 20:11 23:45 (+214)ONT 23:00 02:26 (+206)
11-12SEA 20:11ONT 23:00 23:23 (+23)
11-11SEA 20:11ONT 23:00 22:46 (−14)

Aircraft

Recent tails: N298SY, N316SY.

Board clocks recorded as SEA and ONT published them.

Planning around DL3987? Will a delayed flight be cancelled? · Do planes make up time in the air? · How we measure

Cite this data

Journalists, bloggers, and researchers may cite this page with attribution and a link to Pro Flight Search.

Suggested citation

Pro Flight Search: DL3987 Seattle to Ontario on-time performance, measured from the SEA and ONT airport boards.

Canonical URL
https://proflightsearch.com/flight/DL3987
How we measure this →