US airport delays

What is disrupted right now, from the FAA's live status feed, and how often flights actually ran late, from the Department of Transportation's flight-by-flight records, which arrive about two to three months after the month ends. Back to World Pulse.

Live now — FAA · checked 07:30 UTC

No ground stops, delay programs or reported delays in effect.
6 closure / restriction notices (mostly NOTAMs limiting some aircraft)
LFTClosure!LFT 10/043 LFT AD AP CLSD DLY 0430-0915 2610190430-2610200915
SNAClosure!SNA 10/025 SNA AD AP CLSD DLY 0630-1315 2610200630-2610231315
ASERestricted (NOTAM)!ASE 10/116 ASE AD AP CLSD EXC LIFE FLT HEL AND SAR HEL 30MIN PPR 970-379-8406 2610200500-2610201300
LAXRestricted (NOTAM)!LAX 05/277 LAX AD AP CLSD TO NON SKED TRANSIENT GA ACFT EXC 24HR PPR CTC ATLANTIC AVIATION 310-258-9884 OR SIGNATURE AVIATION 310-410-9605 2605271826-2705281600
LGARestricted (NOTAM)!LGA 10/238 LGA AD AP CLSD EXC HEL 30MIN PPR 718-533-3700 2610200414-2610201000
SANRestricted (NOTAM)!SAN 10/004 SAN AD AP CLSD TO NON SKED TRANSIENT GA ACFT EXC PPR 619-298-7704 2610011633-2701010800
Month Jul 2026 Jun 2026 May 2026 Apr 2026 Mar 2026 Feb 2026 Jan 2026 Dec 2025 Nov 2025 Oct 2025 Sep 2025 Aug 2025 Jul 2025 Measure Departures Arrivals
15%45%+ of departures 15+ min late dot size = flights · ring = FAA program live now

Nationally, July 2025

28.6%
of 615,955 departures ran 15+ min late · usual for July: 25.4% · 2.5% cancelled
Last 37 months · dashed = usual for that month (median of up to 5 earlier years, 2020 left out)
Where late-arrival minutes came from
Late aircraft 41%
Airline 31%
Air traffic 21%
Weather 7%
Security 0%

Airports, July 2025 (departures)

AirportCityFlightsLate 15+ vs usual CancelledAvg minMain cause
ORD Chicago, IL 30,503 35.5% +7.7 2.6% 31 Late aircraft
DEN Denver, CO 29,433 35.8% +3.2 1.5% 30 Late aircraft
DFW Dallas/Fort Worth, TX 28,959 35.8% +5.5 3.1% 28 Late aircraft
ATL Atlanta, GA 28,551 31.0% +4.1 1.6% 24 Airline
LAX Los Angeles, CA 17,104 22.8% -0.8 1.2% 19 Late aircraft
SEA Seattle, WA 16,577 27.8% +10.0 1.4% 18 Airline
CLT Charlotte, NC 16,447 34.6% +3.4 2.3% 28 Late aircraft
LAS Las Vegas, NV 15,733 29.3% -5.8 1.1% 21 Late aircraft
PHX Phoenix, AZ 15,729 26.3% -1.3 1.0% 19 Late aircraft
MCO Orlando, FL 13,579 33.1% -2.4 1.8% 29 Late aircraft
SFO San Francisco, CA 12,958 23.5% +3.3 1.1% 18 Late aircraft
BOS Boston, MA 12,912 27.8% +5.4 4.1% 24 Late aircraft
DCA Washington, DC 12,192 33.0% +7.8 9.5% 34 Late aircraft
LGA New York, NY 11,696 29.8% +4.7 8.8% 31 Late aircraft
DTW Detroit, MI 11,248 26.2% +5.6 2.0% 23 Airline
MSP Minneapolis, MN 10,565 24.8% +6.9 0.9% 20 Airline
EWR Newark, NJ 10,478 30.3% -2.0 6.8% 32 Late aircraft
SLC Salt Lake City, UT 10,346 19.4% +0.4 0.7% 15 Airline
IAH Houston, TX 10,311 31.2% +2.4 1.7% 29 Late aircraft
BNA Nashville, TN 9,459 32.7% +2.9 2.1% 26 Late aircraft
JFK New York, NY 9,262 30.5% +1.0 6.2% 29 Late aircraft
MIA Miami, FL 9,079 34.7% +3.5 2.6% 31 Late aircraft
PHL Philadelphia, PA 9,013 33.4% +9.1 5.2% 35 Late aircraft
BWI Baltimore, MD 8,922 38.0% -0.6 3.6% 33 Late aircraft
SAN San Diego, CA 8,776 26.2% +4.4 1.3% 18 Late aircraft
AUS Austin, TX 7,896 31.2% +5.9 1.6% 26 Late aircraft
MDW Chicago, IL 7,531 36.5% -7.6 1.8% 26 Late aircraft
FLL Fort Lauderdale, FL 6,944 28.6% -5.6 2.2% 25 Late aircraft
TPA Tampa, FL 6,770 29.9% +3.4 1.8% 25 Late aircraft
DAL Dallas, TX 6,349 35.3% +1.4 1.3% 22 Late aircraft
PDX Portland, OR 5,864 21.8% +5.3 1.2% 16 Late aircraft
STL St. Louis, MO 5,855 30.5% +0.3 1.6% 23 Late aircraft
SMF Sacramento, CA 5,494 22.4% +0.1 0.7% 15 Late aircraft
IAD Washington, DC 5,248 28.7% +4.8 2.9% 31 Late aircraft
HNL Honolulu, HI 5,176 15.5% -0.5 1.2% 11 Airline
HOU Houston, TX 5,093 33.3% +0.3 0.8% 21 Late aircraft
RDU Raleigh/Durham, NC 4,907 29.0% +4.0 3.8% 29 Late aircraft
MCI Kansas City, MO 4,442 24.5% +1.8 2.0% 21 Late aircraft
IND Indianapolis, IN 4,222 23.6% +3.5 3.0% 21 Late aircraft
SJC San Jose, CA 4,120 21.0% +2.4 0.9% 13 Late aircraft
MSY New Orleans, LA 4,039 29.8% +1.5 1.8% 25 Late aircraft
SNA Santa Ana, CA 4,002 23.8% +1.7 1.4% 19 Late aircraft
PIT Pittsburgh, PA 3,959 22.0% +0.8 3.3% 19 Late aircraft
CMH Columbus, OH 3,933 26.7% +4.7 3.4% 22 Late aircraft
SAT San Antonio, TX 3,699 22.5% +1.6 1.5% 19 Late aircraft
CLE Cleveland, OH 3,564 23.7% +0.0 3.8% 22 Late aircraft
SJU San Juan, PR 3,415 26.0% -3.4 1.6% 22 Late aircraft
CVG Cincinnati, OH 3,077 27.9% +5.0 2.7% 27 Late aircraft
OAK Oakland, CA 3,046 24.8% +0.8 1.1% 16 Airline
BUR Burbank, CA 2,687 18.9% -1.4 1.7% 14 Late aircraft
MKE Milwaukee, WI 2,589 24.5% +4.5 2.8% 23 Late aircraft
JAX Jacksonville, FL 2,497 30.3% +3.9 3.4% 32 Late aircraft
ONT Ontario, CA 2,394 22.4% +2.0 1.2% 18 Late aircraft
OKC Oklahoma City, OK 2,350 22.1% +0.9 1.9% 20 Late aircraft
ABQ Albuquerque, NM 2,344 22.2% -1.7 1.2% 18 Late aircraft
CHS Charleston, SC 2,331 26.5% -0.4 3.4% 27 Late aircraft
RSW Fort Myers, FL 2,315 24.7% +1.9 2.5% 21 Late aircraft
OMA Omaha, NE 2,312 24.5% +3.0 1.4% 25 Late aircraft
MEM Memphis, TN 2,289 23.2% -2.5 2.4% 20 Late aircraft
ANC Anchorage, AK 2,284 24.2% +8.6 1.5% 16 Late aircraft
OGG Kahului, HI 2,253 16.8% +0.8 1.5% 15 Late aircraft
SDF Louisville, KY 2,176 22.9% +1.1 2.6% 20 Late aircraft
BOI Boise, ID 2,136 17.0% +2.7 0.6% 12 Late aircraft
PBI West Palm Beach/Palm Beach, FL 2,056 28.2% +4.4 4.5% 29 Late aircraft
BDL Hartford, CT 2,015 25.9% -0.6 2.9% 26 Late aircraft
RNO Reno, NV 1,998 22.4% -0.3 0.9% 18 Late aircraft
BUF Buffalo, NY 1,963 28.0% +5.1 4.3% 26 Late aircraft
ORF Norfolk, VA 1,917 32.1% +9.0 5.0% 31 Airline
GEG Spokane, WA 1,873 17.9% +3.1 0.9% 12 Airline
TUL Tulsa, OK 1,803 24.2% +7.5 1.9% 21 Late aircraft
MYR Myrtle Beach, SC 1,767 32.5% +8.7 2.7% 32 Late aircraft
SAV Savannah, GA 1,734 33.8% +5.3 2.8% 34 Late aircraft
RIC Richmond, VA 1,694 29.9% +7.5 4.1% 27 Airline
GRR Grand Rapids, MI 1,691 24.8% +7.0 2.7% 23 Airline
BHM Birmingham, AL 1,601 23.6% -1.7 2.7% 21 Late aircraft
PNS Pensacola, FL 1,498 20.5% -1.7 1.8% 24 Late aircraft
LGB Long Beach, CA 1,473 18.1% -4.8 0.4% 12 Late aircraft
ELP El Paso, TX 1,445 24.3% +2.3 1.0% 19 Late aircraft
TUS Tucson, AZ 1,441 18.3% -0.1 0.9% 18 Late aircraft
LIH Lihue, HI 1,409 14.2% +2.2 1.3% 11 Late aircraft
KOA Kona, HI 1,382 14.3% +1.3 1.0% 11 Late aircraft
DSM Des Moines, IA 1,367 22.0% +4.5 3.5% 25 Airline
BZN Bozeman, MT 1,330 26.5% +3.3 0.8% 22 Air traffic
PVD Providence, RI 1,318 29.3% +3.5 5.0% 29 Late aircraft
GSP Greer, SC 1,316 28.2% +8.4 3.3% 25 Late aircraft
VPS Valparaiso, FL 1,310 23.2% -2.9 1.1% 22 Late aircraft
FAT Fresno, CA 1,289 21.0% +2.4 0.8% 18 Airline
PWM Portland, ME 1,275 28.5% +4.0 6.1% 31 Late aircraft
COS Colorado Springs, CO 1,270 27.5% +1.6 1.9% 25 Late aircraft
TYS Knoxville, TN 1,243 28.3% +9.1 3.2% 34 Late aircraft
SRQ Sarasota/Bradenton, FL 1,237 23.2% -3.5 0.7% 22 Late aircraft
XNA Fayetteville, AR 1,174 23.5% +5.2 2.0% 25 Late aircraft
LIT Little Rock, AR 1,156 30.3% +8.4 1.9% 27 Late aircraft
ALB Albany, NY 1,134 26.2% +0.4 2.6% 27 Late aircraft
ICT Wichita, KS 1,120 22.5% +3.4 2.1% 27 Airline
ECP Panama City, FL 1,092 24.8% +0.1 1.5% 27 Late aircraft
SFB Sanford, FL 1,074 40.0% +11.9 0.4% 36 Airline
AVL Asheville, NC 1,027 28.3% -3.9 2.4% 22 Late aircraft
MSN Madison, WI 1,015 21.9% +2.5 2.6% 26 Airline
PIE St. Petersburg, FL 1,003 26.4% -4.9 0.0% 17 Late aircraft
100 airports with 1,000+ flights this month, busiest first. Click a header to sort.

Airlines — arrivals 15+ min late

AirlineFlightsLateCanc.
Hawaiian7,06620.4%0.7%
SkyWest75,87724.7%1.4%
Delta94,06624.8%1.4%
Spirit17,30724.9%1.9%
Envoy27,48926.4%2.3%
Republic30,39627.3%9.0%
Southwest125,67728.9%1.3%
Allegiant13,97830.1%0.4%
United69,78830.4%1.7%
Alaska23,61930.6%2.2%
PSA21,21430.9%7.1%
JetBlue20,69033.7%5.0%
American87,85235.0%3.4%
Frontier16,40936.0%2.9%
Regional airlines (SkyWest, Envoy, Republic, PSA…) fly under the big brands' names.

Worst days this month

DateAirportLateCanc.
07-13AUS 68%8%
07-25MDW 65%13%
07-31DCA 48%40%
07-10DEN 66%9%
07-13DCA 62%18%
07-14MIA 57%23%
07-13DFW 59%19%
07-14BWI 59%17%
07-13IAH 63%8%
07-27BWI 53%26%
Ranked by share of flights late or cancelled; airports with 150+ flights that day.

FAA programs and delays, last 7 days

AirportWhatStarted (UTC)HoursPeak avgReason
SANDeparture delays 10-20 01:30 1.8 16 min VOL:Compacted Demand
LASGround delay program 10-20 01:00 6.2 48 min other
BOSDeparture delays 10-19 23:00 6.2 16 min RWY:Construction
LGADeparture delays 10-19 20:30 1.5 16 min VOL:Compacted Demand
DCAGround stop 10-19 20:00 0.7 — VIP
LASDeparture delays 10-19 19:00 0.5 16 min WX:Wind
YULGround delay program 10-19 18:00 5.2 79 min runway construction
YULGround delay program 10-19 16:00 1.7 49 min other
LASDeparture delays 10-19 14:45 0.3 16 min OTHER:INDIVIDUAL RELEASES
PHLDeparture delays 10-19 13:45 1.5 16 min VOL:Compacted Demand
TEBDeparture delays 10-19 13:45 1.3 16 min RWY:Maintenance
SANGround delay program 10-19 13:15 15.5 54 min airport volume
SFOGround delay program 10-19 12:45 7.3 55 min low ceilings
SFOGround delay program 10-19 04:00 2.0 58 min low ceilings
SFOGround stop 10-19 03:15 0.8 — low ceilings
LASDeparture delays 10-19 01:00 1.0 16 min WX:Wind
SANGround delay program 10-19 00:45 3.8 52 min airport volume
BOSArrival delays 10-18 20:45 4.5 16 min ZBW / RWY:Construction
LASGround delay program 10-18 19:45 5.3 70 min aircraft emergency
SNADeparture delays 10-18 19:30 2.0 61 min VOL:Compacted Demand
LASDeparture delays 10-18 18:30 1.8 16 min RWY:Disabled Aircraft
LASGround stop 10-18 18:15 1.5 — aircraft emergency
PHXDeparture delays 10-18 18:00 0.2 16 min VOL:Multi-taxi
YULGround delay program 10-18 17:00 5.7 20 min other
PHXDeparture delays 10-18 16:15 0.8 16 min VOL:Multi-taxi
AUSGround delay program 10-18 15:00 6.8 39 min runway construction
SANGround delay program 10-18 14:00 6.0 38 min airport volume
OPFDeparture delays 10-18 13:15 0.3 16 min VOL:Compacted Demand
TEBDeparture delays 10-18 13:15 6.8 76 min STAFF:Staffing
JFKDeparture delays 10-18 01:15 1.3 16 min VOL:Compacted Demand
YVRGround delay program 10-18 00:00 4.5 18 min equipment outage
BOSDeparture delays 10-17 23:15 0.2 16 min RWY:Construction
FLLDeparture delays 10-17 23:15 0.2 16 min TM Initiatives:MIT:WX
MIADeparture delays 10-17 23:00 3.5 31 min TM Initiatives:MIT:WX
BOSDeparture delays 10-17 21:45 0.5 16 min RWY:Construction
LGADeparture delays 10-17 20:45 4.8 76 min TM Initiatives:SWAP:WX
EWRDeparture delays 10-17 20:30 3.0 76 min TM Initiatives:SWAP:WX
LGAGround stop 10-17 20:00 0.5 — wind
EWRArrival delays 10-17 20:00 0.5 31 min ZDC / WX: SEV TURB
TEBDeparture delays 10-17 20:00 3.5 61 min TM Initiatives:SWAP:WX
JFKGround stop 10-17 19:45 1.5 — wind
EWRGround stop 10-17 19:45 1.0 — wind
MIADeparture delays 10-17 19:45 0.8 16 min RWY:Construction
SEADeparture delays 10-17 19:30 2.8 16 min RWY:Construction
SANDeparture delays 10-17 19:00 1.2 16 min VOL:Compacted Demand
EWRGround delay program 10-17 17:00 9.8 67 min other
MCODeparture delays 10-17 16:45 2.3 16 min TM Initiatives:MIT:VOL
MIADeparture delays 10-17 16:45 2.5 61 min RWY:Construction
YVRGround delay program 10-17 16:15 3.0 15 min other
PHXDeparture delays 10-17 16:15 0.7 16 min VOL:Multi-taxi
RSWDeparture delays 10-17 15:45 3.3 16 min WX:Thunderstorms
MIADeparture delays 10-17 14:45 1.3 31 min RWY:Construction
SANGround delay program 10-17 14:00 11.0 53 min airport volume
TEBDeparture delays 10-17 10:30 0.2 16 min INDIVIDUAL RELEASE
LASGround stop 10-17 05:45 0.8 — STAFFING
SANGround stop 10-17 00:45 1.0 — wind
SFOGround delay program 10-17 00:45 3.5 50 min other
YVRGround stop 10-16 23:45 0.8 — OCL:
MCODeparture delays 10-16 23:45 8.0 16 min RWY:Maintenance
BWIDeparture delays 10-16 23:15 8.5 91 min WX:Thunderstorms
LGAGround stop 10-16 22:45 2.3 — thunderstorms
EWRDeparture delays 10-16 22:45 5.3 91 min TM Initiatives:SWAP:WX
BWIGround stop 10-16 22:30 2.0 — thunderstorms
PHXGround delay program 10-16 22:30 5.8 65 min other
IADGround stop 10-16 22:15 1.2 — thunderstorms
DCAGround stop 10-16 22:15 3.0 — thunderstorms
EWRGround stop 10-16 22:15 3.2 — STAFFING
IADDeparture delays 10-16 22:15 5.8 76 min WX:Thunderstorms
PHLDeparture delays 10-16 22:00 6.0 91 min TM Initiatives:SWAP:WX
SFODeparture delays 10-16 21:45 1.3 46 min RWY:Construction
PHLGround stop 10-16 21:15 1.0 — thunderstorms
TEBGround stop 10-16 21:15 2.3 — thunderstorms
JFKGround delay program 10-16 20:30 6.0 60 min thunderstorms
EWRGround delay program 10-16 20:15 6.2 169 min other
LGADeparture delays 10-16 20:15 7.8 136 min TM Initiatives:SWAP:WX
SFODeparture delays 10-16 20:15 0.5 31 min VOL:Multi-taxi
FLLDeparture delays 10-16 19:45 0.7 16 min TM Initiatives:MIT:WX
BOSGround stop 10-16 19:30 0.5 — low ceilings
LASGround stop 10-16 19:15 1.0 — runway maintenance
LGADeparture delays 10-16 18:30 0.5 16 min TM Initiatives:SWAP:WX
SNADeparture delays 10-16 18:30 2.2 16 min VOL:Compacted Demand
MSPGround stop 10-16 18:00 0.7 — wind
TEBDeparture delays 10-16 18:00 10.0 76 min TM Initiatives:SWAP:WX
SNADeparture delays 10-16 17:30 0.2 16 min WX:Wind
SANGround stop 10-16 17:15 2.0 — airport departure volume
YULGround delay program 10-16 17:00 7.2 64 min runway maintenance
SANDeparture delays 10-16 17:00 3.7 31 min WX:Wind
LASGround delay program 10-16 16:45 13.8 80 min wind
SANGround delay program 10-16 16:30 12.2 152 min wind
DFWDeparture delays 10-16 16:30 1.0 16 min WX:Wind
PHXDeparture delays 10-16 16:30 0.2 16 min VOL:Multi-taxi
LGAGround delay program 10-16 16:00 12.0 107 min thunderstorms
IAHDeparture delays 10-16 16:00 0.2 16 min WX:Wind
SANGround stop 10-16 15:45 0.8 — wind
PHLGround delay program 10-16 15:45 8.5 57 min thunderstorms
AUSGround delay program 10-16 15:15 7.0 66 min runway construction
AUSGround stop 10-16 15:00 0.2 — runway construction
TEBDeparture delays 10-16 15:00 0.5 31 min TM Initiatives:SWAP:WX
DFWDeparture delays 10-16 14:30 0.8 16 min WX:Wind
EWRDeparture delays 10-16 14:15 0.8 46 min TM Initiatives:SWAP:WX
PHLDeparture delays 10-16 14:15 2.5 46 min WX:Thunderstorms
DCAGround delay program 10-16 12:30 15.5 211 min thunderstorms
BOSGround delay program 10-16 12:15 12.5 101 min low ceilings
EWRDeparture delays 10-16 12:00 1.2 46 min TM Initiatives:SWAP:WX
BHMGround delay program 10-16 06:00 0.2 7 min equipment outage
SEAGround stop 10-16 02:30 0.7 — runway construction
DFWGround stop 10-16 02:15 0.5 — wind
SEADeparture delays 10-16 01:30 0.2 16 min RWY:Construction
ORDGround delay program 10-16 00:45 3.3 81 min other
DFWGround delay program 10-15 23:45 3.0 51 min thunderstorms
BOSDeparture delays 10-15 23:30 2.8 31 min RWY:Construction
SEADeparture delays 10-15 23:30 0.2 16 min RWY:Construction
ORDGround stop 10-15 23:15 1.5 — thunderstorms
DFWGround stop 10-15 22:15 1.5 — wind
YYCGround delay program 10-15 22:00 2.7 31 min runway construction
ORDDeparture delays 10-15 21:45 4.5 16 min WX:Low Ceilings
BFIDeparture delays 10-15 19:00 0.3 16 min VOL:Volume
TEBDeparture delays 10-15 19:00 2.8 31 min VOL:Multi-taxi
SFODeparture delays 10-15 18:30 1.0 16 min VOL:Multi-taxi
PHXDeparture delays 10-15 16:15 0.8 16 min VOL:Multi-taxi
SANDeparture delays 10-15 16:15 10.0 46 min VOL:Compacted Demand
SEADeparture delays 10-15 16:15 0.3 16 min RWY:Construction
SFOGround stop 10-15 16:00 0.8 — airport volume
YULGround delay program 10-15 16:00 7.2 17 min runway construction
MIADeparture delays 10-15 15:30 0.7 16 min RWY:Construction
SEAGround stop 10-15 15:15 1.3 — low visibility
SEADeparture delays 10-15 15:00 0.2 16 min WX:Fog
DENGround stop 10-15 14:15 1.0 — low ceilings
SANGround delay program 10-15 14:00 14.8 39 min airport volume
DFWDeparture delays 10-15 14:00 1.2 46 min WX:Thunderstorms
TEBDeparture delays 10-15 13:45 0.8 16 min VOL:Multi-taxi
YVRGround stop 10-15 13:00 0.7 — fog
BOSGround delay program 10-15 11:45 7.5 12 min runway construction
DFWDeparture delays 10-15 00:15 2.5 16 min WX:Thunderstorms
JFKDeparture delays 10-14 23:45 1.3 16 min RWY:Construction
BWIDeparture delays 10-14 23:30 2.0 46 min WX:Thunderstorms
BWIDeparture delays 10-14 22:45 0.5 16 min WX:Thunderstorms
DALDeparture delays 10-14 21:45 0.3 16 min WX:Thunderstorms
DFWDeparture delays 10-14 21:15 1.0 16 min WX:Thunderstorms
DALDeparture delays 10-14 21:00 0.2 16 min WX:Thunderstorms
LASDeparture delays 10-14 21:00 1.2 16 min STAFF:Staffing
DFWDeparture delays 10-14 20:30 0.2 16 min WX:Thunderstorms
DALDeparture delays 10-14 20:15 0.5 16 min WX:Thunderstorms
BOSGround stop 10-14 20:00 0.7 — runway construction
DENGround delay program 10-14 19:45 7.2 61 min low ceilings
DALDeparture delays 10-14 19:15 0.5 31 min WX:Thunderstorms
YULGround delay program 10-14 18:29 4.5 12 min airport volume
BOSGround delay program 10-14 18:29 4.8 66 min runway construction
AUSGround delay program 10-14 18:29 4.8 59 min runway construction
SANDeparture delays 10-14 18:29 1.0 31 min VOL:Compacted Demand

Most disrupted, last 30 days (FAA)

AirportGSGDPDelayHours
SAN36585
BOS23540
LAS33533
YUL06032
EWR22531
LGA21429
TEB10828
PHL11320
DCA21019
AUS13019
SFO23317
BWI10313
DFW21612
MCO00210
JFK11210
Recording since 2026-10-14. The FAA keeps no public history, so this is only what we have polled (every 15 minutes).
Sources. Delay rates: US DOT Bureau of Transportation Statistics, Reporting Carrier On-Time Performance (public domain). It covers domestic flights on airlines with at least 0.5% of US domestic passenger revenue, about 600,000 flights a month; smaller carriers and international flights are not in it. Live status: FAA Air Traffic Control System Command Center, NAS Status (public domain). Airport locations: OurAirports (public domain).
Definitions. Late means 15+ minutes after schedule, out of flights that operated. Causes are reported by airlines for arrivals 15+ minutes late. "Late aircraft" is the knock-on from an earlier delay to the same plane, so it says nothing about where the trouble started. "Air traffic" (the NAS category) covers airport capacity, traffic volume and non-extreme weather. "Usual" is the median of the same month in up to five earlier years, with 2020 left out; it appears once two earlier years exist.