Airport month record
OAKMAY
Oakland International in May 2026
- Departures
- 2,683
- Month
- May 2026
- National, same month
- 78.6%
- Carriers
- 3
Historical statistics for May 2026, not live status or a forecast for this year’s May. For today’s conditions at OAK, see live FAA status.
OAK in May lands a B+, 3 points worse than the national rate of 78.6%. About one flight in four arrives 15 minutes late or worse, and those flights are late by about 50 minutes on average. That is a workable record, not a spotless one. That rests on 2,683 flights, with a median arrival 3 minutes early.
Key figures
On time
76.1%
Arrivals under 15 minutes late, of 2,664 completed departures
Avg delay
50 min
Across delayed arrivals only, not all flights
Cancelled
0.63%
Nationally in May: 0.92%
Whole year
79.5%
OAK across all twelve months
These figures cover 2,683 departures from Oakland International in May 2026. On time means an arrival less than 15 minutes after the scheduled gate time, the DOT's threshold, and the national comparison uses every US departure in the same month rather than the whole year.
Against the year
May next to OAK's other months
Against OAK's own year, May ran 3 points worse than the twelve-month rate of 79.5%, which makes it number eleven of twelve months, best first. Either side of it, April ran 76.4% on time and June 69.7%, so a trip moved by a few weeks would have landed in a worse stretch.
| Month | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| July 2025 | 3,046 | 78.4% | 62 min | 1.05% | B |
| August 2025 | 2,850 | 81.4% | 58 min | 0.35% | B+ |
| September 2025 | 2,714 | 82.4% | 47 min | 0.29% | B+ |
| October 2025 | 2,771 | 79.6% | 52 min | 0.25% | B+ |
| November 2025 | 2,618 | 81.6% | 56 min | 2.06% | B |
| December 2025 | 2,646 | 76.7% | 50 min | 0.57% | B+ |
| January 2026 | 2,408 | 88.4% | 54 min | 0.46% | A+ |
| February 2026 | 2,356 | 83.7% | 50 min | 0.25% | B+ |
| March 2026 | 2,569 | 80.1% | 53 min | 0.97% | B+ |
| April 2026 | 2,509 | 76.4% | 46 min | 0.28% | B+ |
| May 2026 (this page) | 2,683 | 76.1% | 50 min | 0.63% | B+ |
| June 2026 | 2,597 | 69.7% | 49 min | 0.42% | C+ |
Departure window
The best time of day to leave OAK in May
Departure time matters more here than the choice of carrier. The gap between the best and worst window is 35 points, against half a point between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.
- 5am–8am537 flights94.2%
- 8am–11am461 flights87.0%
- 11am–2pm470 flights74.8%
- 2pm–5pm493 flights68.4%
- 5pm–8pm405 flights63.8%
- 8pm–5am317 flights59.6%
Scale runs 50% to 100%. Rows with fewer than 30 flights show a dash.
The 8pm–5am window is where this operation falls apart: 59.6% on time, against 94.2% for the 5am–8am slot. By evening the aircraft flying these rotations have absorbed a full day of small delays and there is no slack left to recover in. The 5am–8am window is the busiest, with 537 flights scheduled in it.
Across the week, Saturday is the strongest day at 90.9% on time and Thursday the weakest at 69.1%. 22 points is a smaller lever than departure hour, but it is free.
Carrier by carrier
Which airlines ran best at OAK in May
Only one carrier clears this site's 365-flight floor here, so there is no comparison to draw. The table below is the full picture.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| Southwest Airlines | 2,303 | 74.9% | 50 min | 0.61% | C+ |
| SkyWest Airlinesthin sample | 217 | 78.7% | 44 min | 0.46% | B+ |
| Alaska Airlinesthin sample | 155 | 91.5% | 50 min | 1.29% | A |
Route by route
Busiest routes out of OAK in May
| Route | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| OAK to SAN · San Diegothin sample | 339 | 60.5% | 44 min | 0.59% | D+ |
| OAK to LAS · Las Vegasthin sample | 285 | 72.2% | 50 min | 1.40% | C |
| OAK to BUR · Burbankthin sample | 219 | 84.3% | 64 min | 1.37% | B |
| OAK to SNA · Santa Anathin sample | 201 | 91.5% | 40 min | 1.00% | A |
| OAK to PHX · Phoenixthin sample | 179 | 72.1% | 53 min | 0.00% | C+ |
| OAK to LAX · Los Angelesthin sample | 176 | 78.4% | 52 min | 0.00% | B+ |
| OAK to SLC · Salt Lake Citythin sample | 141 | 81.6% | 78 min | 0.00% | B+ |
| OAK to DEN · Denverthin sample | 128 | 65.9% | 42 min | 0.78% | C+ |
| OAK to SEA · Seattlethin sample | 124 | 80.6% | 36 min | 0.00% | B+ |
| OAK to LGB · Long Beachthin sample | 118 | 88.0% | 37 min | 0.85% | A+ |
| OAK to ONT · Ontariothin sample | 117 | 74.4% | 49 min | 0.00% | C+ |
| OAK to PDX · Portlandthin sample | 111 | 70.3% | 50 min | 0.00% | C+ |
| OAK to PSP · Palm Springsthin sample | 70 | 63.8% | 55 min | 1.43% | D |
| OAK to HNL · Honoluluthin sample | 62 | 79.0% | 36 min | 0.00% | B+ |
| OAK to LIH · Lihuethin sample | 62 | 88.3% | 61 min | 3.23% | A− |
| OAK to OGG · Kahuluithin sample | 62 | 91.9% | 76 min | 0.00% | A+ |
| OAK to MDW · Chicagothin sample | 52 | 84.6% | 29 min | 0.00% | B+ |
| OAK to DAL · Dallasthin sample | 40 | 68.4% | 60 min | 2.50% | C |
| OAK to BOI · Boisethin sample | 35 | 82.9% | 72 min | 0.00% | B+ |
| OAK to AUS · Austinthin sample | 31 | 77.4% | 45 min | 0.00% | B+ |
| OAK to SBA · Santa Barbarathin sample | 31 | 87.1% | 47 min | 0.00% | A+ |
| OAK to ABQ · Albuquerquethin sample | 31 | 58.1% | 58 min | 0.00% | D+ |
| OAK to HOU · Houstonthin sample | 31 | 80.6% | 39 min | 0.00% | B+ |
| OAK to GEG · Spokanethin sample | 30 | 76.7% | 44 min | 0.00% | B+ |
Delay causes
What held OAK up in May
One category carries most of the weight here. Late-arriving aircraft accounts for 52% of the 32,000 delay minutes carriers reported, and the remaining four split what is left. The split is by minutes rather than by flights, so a few very long delays count for as much as many short ones.
- 52%Late-arriving aircraft
- 33%Carrier
- 14%National Airspace System
- 1%Extreme weather
- 0%Security
52% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. That is a cascade, and cascades start small and grow through the day. Across 32,000 reported delay minutes here, that single category outweighs weather by 52 to one. It is the strongest argument for booking the first departure of the morning, when the aircraft has been sitting at the gate overnight with nothing to inherit. The split is drawn from 31,697 reported delay minutes.
Cancellations are rare at 0.63%, below the national 0.92% and low enough to earn the plus on the grade. Roughly one flight in 100 is called off; the risk here is arriving late, not not arriving.
6.0% of arrivals land an hour or more late, close to the national 7.1%. That is the figure that decides a connection, and it says a 60 to 75 minute layover is reasonable here while anything under 45 minutes is a bet. Most delays on this route last about 50 minutes, which a normal layover absorbs.
What to do with this
Flying from OAK in May
For a May trip through OAK: plan on this being one of the airport's harder months. The 5am–8am departures held up best at 94.2% on time, and with 6.0% of arrivals an hour or more late, a connection here deserves more slack than the same trip in January would.
Related
Where to go next
- Oakland International (OAK), the whole year
- OAK in July78.4%
- OAK in August81.4%
- OAK in September82.4%
- OAK in October79.6%
- OAK in November81.6%
- OAK in December76.7%
- OAK in January88.4%
- OAK in February83.7%
- OAK in March80.1%
- OAK in April76.4%
- OAK in June69.7%
Source: US DOT Bureau of Transportation Statistics, on-time performance data, July 2025 to June 2026. Last updated 15 September 2026; recomputed monthly. How this data is collected.