Skip to content
WanderNerd
Check a flight

Flight Reliability

AS 21 · Alaska Airlines

New York → Seattle (JFK–SEA)

58
A Little Dicey
WanderNerd Reliability Score
67%
Arrive within 15 minutes
10 min
Average arrival delay
3.9%
Cancelled
3 min
Median arrival delay

Based on 359 historical flights. Data through May 2026.

What the data says

The 3–6 PM departure wins.

AS 21 departing between 3–6 PM arrived on time 74% of the time, versus 67% between 6–9 AM.

Friday is doing you no favors.

AS 21 arrived on time 75% of the time on Tuesdays. On Fridays: 62%.

Lagging the Alaska Airlines network.

AS 21 arrived on time 67% of the time, versus 80% across the Alaska Airlines network.

Keep a backup plan handy.

AS 21 was cancelled 3.9% of the time. Typical for U.S. flights is around 1–2%.

The breakdown

On-time by weekday
  • Mon64%(50 flights)
  • Tue75%(48 flights)
  • Wed67%(51 flights)
  • Thu67%(49 flights)
  • Fri62%(50 flights)
  • Sat62%(45 flights)
  • Sun71%(51 flights)
On-time by departure window
  • 6–9 AM67%(325 flights)
  • 3–6 PM74%(19 flights)
On-time trend by month
77%
May

Jun 57% → May 77% on time

On-time arrival percentage by month
MonthOn-time percentageFlights
June 202557%28
July 202577%30
August 202553%30
September 202593%29
October 202583%29
November 202579%29
December 202524%29
January 202650%26
February 202674%23
March 202639%31
April 202697%29
May 202677%31
Departures on time
86%
Diverted
0.3%
Flights flown
344
Months covered
12

Same route, other flights

Keep nerding

Based on 359 historical flights, because apparently we checked. Historical flight data: U.S. Bureau of Transportation Statistics, June 2025 – May 2026. Data through May 2026. How we calculate this.