BOS · Boston Logan International Airport

Share of flights 15+ min late, by month

departures arrivals usual for the month (departures) Jan 2015 → Jul 2026; gridlines 10/20/30/40%

Month	Flights	Late 15+	vs usual	Cancelled	Avg min	Main cause
Jul 2026	13,277	30.3%	+3.7	5.9%	26	Late aircraft
Jun 2026	12,683	21.6%	-3.4	1.8%	17	Late aircraft
May 2026	12,694	18.0%	-4.2	0.6%	13	Late aircraft
Apr 2026	12,626	20.2%	+1.7	0.3%	14	Late aircraft
Mar 2026	12,299	23.8%	+5.4	2.7%	18	Late aircraft
Feb 2026	10,232	23.8%	+2.5	8.2%	19	Late aircraft
Jan 2026	10,298	21.8%	+2.4	7.5%	18	Airline
Dec 2025	11,248	27.1%	+3.5	1.7%	21	Late aircraft
Nov 2025	11,385	20.2%	+6.2	2.8%	17	Late aircraft
Oct 2025	12,647	28.3%	+10.7	1.5%	22	Late aircraft
Sep 2025	11,597	26.1%	+10.0	1.4%	21	Late aircraft
Aug 2025	12,461	19.9%	-3.9	1.0%	14	Late aircraft
Jul 2025	12,912	27.8%	+5.4	4.1%	24	Late aircraft
Jun 2025	12,372	25.1%	+0.6	1.3%	20	Late aircraft
May 2025	12,547	24.2%	+3.7	0.8%	19	Late aircraft
Apr 2025	12,413	17.1%	-5.0	0.3%	12	Airline
Mar 2025	12,361	18.4%	-1.4	0.6%	15	Late aircraft
Feb 2025	10,292	22.3%	+1.0	2.5%	19	Air traffic
Jan 2025	10,624	15.2%	-5.8	2.4%	11	Air traffic
Dec 2024	11,778	23.6%	+4.8	1.4%	18	Late aircraft
Nov 2024	11,756	14.0%	-1.8	0.1%	10	Airline
Oct 2024	13,035	13.4%	-5.1	0.8%	9	Airline
Sep 2024	12,359	16.1%	-1.7	0.4%	12	Airline
Aug 2024	13,215	26.8%	+2.9	3.7%	23	Late aircraft

Airline	Flights	Late	Canc.
United	919	10.4%	1.2%
American	1,096	11.3%	2.6%
Republic	2,461	11.8%	3.3%
Southwest	424	13.0%	4.0%
Alaska	115	13.0%	0.0%
Spirit	443	13.1%	3.6%
Envoy	146	14.2%	3.4%
Delta	1,832	17.9%	1.3%
JetBlue	2,976	19.2%	2.2%
Frontier	178	31.2%	2.8%

Airlines with 30+ departures that month.

Date	Flights	Late	Canc.
2015-01-27	306	—	100%
2022-01-29	246	—	100%
2026-02-23	396	—	100%
2018-03-13	424	0%	100%
2026-01-26	356	90%	78%
2015-02-15	266	82%	86%
2019-03-04	442	94%	42%
2015-02-02	323	62%	89%
2022-02-25	387	83%	73%
2019-01-20	290	75%	78%
2020-12-17	165	86%	52%
2018-01-04	355	7%	92%

Departures; ranked by share late or cancelled.