Shannon to Dulles (SNN–IAD) — 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.

Silver Line Metro runs from Washington Dulles Airport station to Metro Center in about 65 minutes (~$7). The route bypasses I-66 and I-495 congestion entirely. Washington Flyer coach also runs to Wiehle-Reston East station ($6, 15 min) for Metro connection.Taxis and ride-shares to downtown DC cost $55–80 and take 35–55 minutes depending on traffic. Car rental facilities are on-site. Dulles is 27 miles west of the Capitol; it is farther than either DCA or BWI from central DC.

Humid continental climate. Summers are hot and muggy (30–36°C) with frequent afternoon thunderstorms that cause delays June through August. Winters bring cold temperatures (−3 to 5°C) with snow and ice. The Virginia suburbs accumulate more snow than downtown DC, and ice storms are the primary disruption risk.

Dulles sits at higher elevation in Virginia's piedmont and sees more winter precipitation than DCA. Spring and fall are variable. Snowfall is possible into April. Thunderstorms begin from April through May.