Two Weeks Out of Thirty-Five: How Often Lisbon's Airport Respected Its Night-Flight Limit This Year
ZERO counts 4,647 movements between midnight and six since January, 1,465 of them above the legal ceilings, and has launched a public tracker. It is 536 days since the government announced a curfew between 01:00 and 05:00 that is still not in force.
For 33 of the 35 weeks Portugal has had so far in 2026, Lisbon's airport put more aircraft into the sky between midnight and six in the morning than the law allows. In two weeks it did not. That ratio is the finding published on Friday by ZERO, Associação Sistema Terrestre Sustentável (Sustainable Land System Association), which has also built a public page, at aerovoos.zero.ong, where anyone can now follow the count night by night using movement data from the flight-tracking site Flightradar24.
What the ceilings are, and how far past them
Portaria n.º 303-A/2004, a ministerial order, restricts traffic at Humberto Delgado between 00:00 and 06:00 and sets two limits: 91 movements per week and 26 per night. A movement is one landing or one take-off.
Since January, ZERO counts 4,647 movements in that window. The weekly cap was passed in 33 of 35 weeks and the nightly cap on 23 separate nights, for 1,465 movements above the limits. August was the worst month: in the week of 17 to 23 August there were 187 movements, 96 more than permitted and more than double the ceiling. The second worst week ran 4 to 10 May, at 94 over, and the third was 24 to 30 August, at 92 over. On the four heaviest nights, 30 March, 10 May, 29 March and 24 August, the airport recorded 48, 46, 43 and 43 movements against a limit of 26.
ZERO makes the caveat itself: the legislation admits exceptions, so a numerical excess is not automatically an infringement. It wants the Autoridade Nacional da Aviação Civil (National Civil Aviation Authority, ANAC) to say publicly which movements are covered by an exception, which are genuine breaches, and what follows. That question has form: when we reported 870 night-flight violations across a single quarter in April, the fine that followed was symbolic and was appealed.
The four hours that were promised
In March 2025, through Resolução do Conselho de Ministros n.º 58/2025 (Council of Ministers Resolution) of 18 March, the government announced a hard curfew between 01:00 and 05:00. ZERO counts 536 days since. The curfew is not in force, and 1,165 of this year's night movements fell inside precisely those four hours.
Who is underneath, and what is being spent
The Noise Action Plan identifies 63,879 people exposed at night to levels above 55 dB(A), the national limit near airports, out of more than 370,000 exposed to aircraft noise in total. The World Health Organization recommends night-time averages below 40 dB(A).
Against that, the Plano de Ação de Ruído 2024-2029 (Noise Action Plan) carries seven million euros for mitigation, plus ten million announced for acoustic insulation through the Fundo Ambiental (Environmental Fund). ZERO calls the sums manifestly insufficient and says they should fall on ANA, Aeroportos de Portugal, the concession holder, under the polluter-pays principle. Its comparison is Madrid, where AENA has invested more than 155 million euros since 2000 and treated 12,924 homes at Barajas, an airport whose comparable night-exposed population it puts at about 1,800.
The argument matters most for what comes next. ANA wants the hourly movement cap lifted from 38 to 40, with 42 already in view. ZERO's own 2025 sample found 28 percent of daytime hours already above 38 and a peak of 45 in one hour, and argues the increase cannot be shown compatible with the noise limits. Its answer is speed on the replacement airport at Alcochete and a definitive closure of Portela.
Aircraft sit outside the ordinary noise regime, which is why the tracker exists at all. For everything else, our guide to the Regulamento Geral do Ruído sets out the 23:00 to 07:00 rule and how to complain.
