Shannon to Phoenix (SNN–PHX) — Airlines, Schedules & Connections

Irish passport holders enter the United States visa-free under the Visa Waiver Program (VWP) for stays up to 90 days. An approved ESTA (Electronic System for Travel Authorization) is required before boarding. The ESTA costs $21, is valid for 2 years or until the passport expires (whichever comes first), and covers multiple entries. Apply at esta.cbp.dhs.gov at least 72 hours before departure, though most approvals come within minutes.

Passport must be an ePassport (biometric chip, all current Irish passports qualify). No supporting documents are formally required for ESTA approval, but CBP officers at the port of entry may ask for proof of onward travel, accommodation details, and sufficient funds. The 90-day VWP stay cannot be extended and does not allow a change of immigration status. If you need more than 90 days, apply for a B-1/B-2 visa at the US Embassy in Dublin (MRV fee $185, interview wait times vary from 1 to 6 weeks).

Direct flights from Dublin to the US serve New York (JFK/EWR), Boston, Chicago, Washington Dulles, Los Angeles, San Francisco, and several others, running 7 to 10 hours. Shannon also has direct US routes. US Customs and Border Protection preclearance operates at Dublin and Shannon, meaning you clear US immigration before boarding and arrive as a domestic passenger. The US dollar is the only currency. No vaccination requirements for Irish arrivals.

PHX Sky Train (free, 24h) connects T3 and T4 to the 44th Street/Washington light rail station in 5 minutes. Valley Metro Rail reaches downtown Phoenix in 20 minutes ($2). Uber and Lyft pick up at Ground Transportation on the lower level; follow signs. Taxis are metered; downtown Phoenix costs $20–30.Rental car agencies are consolidated in the Rental Car Center; the Sky Train connects there from both terminals without going to the street. For Scottsdale, Tempe, or Chandler, ride-hails are practical ($25–50). Express buses serve some suburban destinations.

Hot desert climate. Summers (June–September) are extreme. Daytime temperatures regularly exceed 43°C, occasionally reaching 48°C. Heat alone rarely cancels flights, but density altitude affects small aircraft performance. Monsoon season (July–mid-September) brings dramatic dust storms (haboob) that close the airport when they hit, plus intense flash-flooding thunderstorms that ground departures for 30–90 minutes.

Winters are exceptionally mild (10–22°C) with virtually no precipitation and near-constant sunshine. PHX has one of the lowest weather cancellation rates of any major US airport from November through April. Spring and fall are pleasant; late May and early June are hot and dry before monsoon arrives.