The flying time to Lisbon is 6½ hours from New York on a direct flight; it's 10 hours from Chicago and 15 hours from Los Angeles on indirect flights. The flight from London to Lisbon is just under 3 hours.
Note that some budget airlines, such as Irish low-cost airline Ryanair, only allocate seats for an extra fee. Also, Ryanair and U.K.-based easyJet generally don't serve meals but do sell (overpriced) sandwiches, drinks, and other items. If you're on a special diet, pack appropriate snacks in your carry-on bag.
When traveling with most European low-cost airlines you’ll have to pay to check in a suitcase (32 kilograms or 70½ pounds max), but one carry-on case per person is free as long as it complies with the airline’s specific cabin measurements and weight.
The major gateway to Portugal is Lisbon's Aeroporto Portela (LIS), approximately 8 km (5 miles) northeast of the center of the city. The underground Lisbon Metro runs from Terminal 1. Arrivals to the city center are about every 6–9 minutes from 6:30 am to 1 am (16 minutes, €1.40). An AeroBus also departs from outside Arrivals and goes to the city center (45 minutes, €3.15) roughly every 20 minutes from 7 am to 11 pm.
Porto's Aeroporto Francisco Sá Carneiro (OPO) also handles international flights and, like Lisbon, operates an AeroBus to the city center (25 minutes, €4) from 7:30 am to 8 pm. The Aeroporto de Faro (FAO) handles the largest number of charter flights because of its location in the popular tourist destination of the Algarve. Several buses run into town (15 minutes, €1.95), while a taxi will cost approximately €12.
The organization that oversees Portugal's airports, Aeroportos de Portugal (ANA), has a handy website with information in English.
Aeroporto de Faro. Faro, Faro, 8006-901. 289/800800.
Aeroporto Francisco Sá Carneiro. Porto, Porto, 4470-558. 229/432400.
Aeroporto Portela. Lisbon, Lisbon, 1700-111. 21/841–3500.
Domestic air travel can be a good value between major cities, such as Porto and Lisbon or Lisbon and Faro, though prices tend to increase during the busy summer months.
TAP Air Portugal has daily nonstop flights from New York (Newark Liberty International Airport) to Lisbon and Porto with connections to Faro and Madeira. United's daily nonstop flights between Newark Liberty International Airport and Lisbon are scheduled to provide convenient connections from destinations elsewhere in the eastern and southern United States.
British Airways, TAP, Ryanair, and easyJet have regular nonstop flights from the United Kingdom to several destinations in Portugal. From Spain, TAP, Iberia, and easyJet have daily Madrid–Lisbon flights; TAP, Vueling, and Iberia fly daily nonstop from Barcelona to Lisbon. From the Netherlands, KLM, TAP, easyJet, and Transavia have frequent nonstop flights from Amsterdam to several Portuguese cities.
Consider flying to London first and picking up an onward no-frills budget airline or charter flight: you might save money and have a wider choice of destinations in Portugal. There are often good deals to Faro in particular, because the Algarve is popular with British vacationers. In summer, last-minute, round-trip flights have cost as little as $150.
British Airways. www.ba.com.
TAP Air Portugal. www.flytap.com.