Flight delays and airport impacts: September 29, 2025
Low clouds in the Northwest, afternoon storms over Florida and the Rockies, and major runway work in Boston shape today's outlook. The FAA's operations plan highlights potential ground stops or delay programs at San Francisco, Boston, and Denver later in the day, with oceanic routes south of New York remaining closed due to tropical weather over the Atlantic. Seattle is already seeing arrival delays tied to low ceilings and gusty winds. Travelers should build in extra time and monitor airline alerts.
Key points
- Why it matters: Weather and construction combine to push schedule pressure at multiple hubs.
- Travel impact: Arrival delays at Seattle; programs possible later at San Francisco, Boston, and Denver.
- What's next: FAA webinar updates and midday re-planning may add or remove initiatives.
- Oceanic routes L451-L459 closed due to tropical storm impacts south of New York.
- Boston Runway 09/27 closed through mid-November; taxiway and runway work continues at several hubs.
- Thunderstorms likely in Florida and along Front Range could trigger reroutes and holding.
Snapshot
The FAA's 1142 a.m. ET planning advisory calls out low ceilings at Seattle, San Francisco, and Charlotte, with thunderstorms expected in Florida and Denver later today. Terminal programs are not active as of publication, but ground stop or delay programs are possible after 330 p.m. at San Francisco, after 500 p.m. at Boston, and after 700 p.m. at Denver. A separate advisory places Seattle arrivals on expected delays up to 30 minutes due to ceilings and gusts. Oceanic routes L451-L459 remain closed amid tropical weather, which can add time to transatlantic flights that normally use those tracks. Expect miles-in-trail and swaps across Northeast and Florida centers.
Background
Runway and taxiway projects continue to constrain capacity at several large airports at the tail end of construction season. Boston Logan's Runway 09/27 is closed through November 15, while Tampa's Runway 01R/19L and Orlando's Runway 18R/36L remain offline into October and November, respectively. Similar work is underway at LaGuardia, Denver, San Francisco, Houston Intercontinental, Salt Lake City, Indianapolis, and Chicago O'Hare. Separately, the FAA recently extended slot relief and flight caps at Newark through October 2026 to ease congestion across the New York area. Seasonal storm patterns in Florida and the Rockies add convective risk during peak push periods, with the Aviation Weather Center flagging thunder potential and traffic managers planning for capping, tunneling, and escape routes.
Latest developments
Low ceilings drive early delays at Seattle; programs possible for SFO, BOS, DEN
Seattle arrivals face delays or holding of up to 30 minutes due to low ceilings and gusty winds, with the constraint window expected into the evening. The FAA's operations plan lists low ceilings at Seattle and San Francisco, storms for Florida and Denver, and staffing-related mitigation at Philadelphia earlier today. While no terminal initiatives were active at press time, traffic managers may implement ground stops or delay programs after 330 p.m. at San Francisco, after 500 p.m. at Boston, and after 11:00 p.m. at Denver if weather or demand require it. Oceanic track closures L451-L459 persist, and Lake Erie west routes remain in play for cross-border traffic. Expect potential CDRs and SWAP for Potomac, New York/Philadelphia, Orlando, Atlanta, and Phoenix during the afternoon peaks.
Construction watch: Boston, Tampa, Orlando, Houston, San Francisco
Runway 09/27 at Boston is closed through November 15, reducing arrival and departure flexibility during east-wind operations. Tampa's 01R/19L remains closed until October 26; Orlando's 18R/36L is closed until November 14, and Houston Intercontinental's 08R/26L is closed until November 11. LaGuardia continues night and weekend runway and taxiway closures through September 30, while O'Hare, Salt Lake City, and Denver have ongoing taxiway and runway work that can add taxi-out and sequencing delays. San Diego's multi-phase airfield project continues into February 2026, and San Francisco's Taxiway Z rehabilitation runs into mid-November.
Northeast easing but oceanic reroutes linger; Atlantic tropical weather in the mix
The plan notes "good weather and outlook" for the New York TRACON airports today, but oceanic route closures south of New York continue due to tropical storm impacts. Flights normally using those routes may see longer routings and minor schedule drift. Potomac TRACON will manage compacted demand and a brief Arlington flyover at Washington Reagan National, which can create short-term spacing. Expect miles-in-trail, swaps, and regional routes through the afternoon in the Northeast and Florida centers.
Analysis
Today's risk skew is moderate, with the first-order driver being low clouds at West Coast terminals and diurnal storms over Florida and the Front Range. Seattle sits at the top of the watchlist given the active arrival-delay advisory and a lingering marine layer pattern that can limit arrival rates and force holding. San Francisco's complex airspace and propensity for ceiling-driven initiatives make the late-afternoon window the second-highest risk for programs, especially if push banks bunch up. Boston's runway closure compresses configuration options; a late-day ground delay program is plausible if winds shift or sequenced departures stack. Denver's convective timing near the evening departure push is a classic trigger for airborne holding and reroutes. Oceanic route closures are a low-frequency, high-impact constraint for specific flows; most domestic travelers will not notice, but transatlantic schedules can drift. Construction-related closures at Tampa, Orlando, and Houston reduce recovery elasticity should storms flare, so small weather hiccups may produce outsized delay banks.
For planning, travelers should build in 60 to 90 minutes of connection padding for itineraries touching SEA, SFO, BOS, or DEN this afternoon and evening. Consider earlier departures to dodge pop-up programs, and keep an eye on carrier rebooking policies tied to weather or ATC initiatives. Advisors should pre-warn clients about runway projects at major hubs through October and November.
Final thoughts
Expect a mostly manageable day outside the named hotspots, with rolling traffic-management initiatives possible in the mid- to late-afternoon peaks. If you are booked through Seattle, San Francisco, Boston, or Denver, set airline alerts and watch for gate-hold or revised wheels-up times. Construction and oceanic reroutes add background friction but should not overwhelm the system barring a storm burst. Build a sensible cushion, and you will be positioned to navigate any flight delays.