Madrid to Houston (MAD–IAH) — Airlines, Schedules & Connections

Spain is part of the US Visa Waiver Program. Spanish passport holders can enter the US for tourism or business for up to 90 days with an approved ESTA (Electronic System for Travel Authorization). Apply at esta.cbp.dhs.gov at least 72 hours before departure. The fee is USD 21. The ESTA is valid for 2 years or until your passport expires, whichever comes first. It covers multiple entries.

Your passport must be machine-readable and, for VWP travel, must be an ePassport (the kind with the chip symbol on the cover). Spanish passports issued after 2006 meet this requirement. The 90-day ESTA stay cannot be extended and cannot be changed to another visa status from inside the US. If you need more than 90 days, apply for a B-1/B-2 visa at the US Embassy in Madrid.

US border officers have wide discretion. Have your return flight, hotel address, and a general itinerary ready. ESTA approval does not guarantee entry. The CBP officer makes the final decision at the port of entry. Global Entry (USD 100, 5-year membership) speeds up arrivals significantly at US airports if you travel frequently.

Metro Line 8 runs from Nuevos Ministerios (central Madrid) to T1/T2/T3 in 12–15 minutes (€6, including the airport supplement). T4 requires an additional free shuttle from T2; add 10 minutes. The Cercanías commuter train (Line C-1) reaches T4 from Atocha station in 25 minutes (€2.60, no supplement).Taxis have a fixed fare of €30 from central Madrid zones. The ride is typically 20–35 minutes depending on traffic. Avenida de América bus hub serves several airport bus routes (€5).

No direct rail from IAH. The METRO bus 102 (IAH Express) runs to downtown Houston's transit center (60–90 min, $1.25). Taxis to downtown Houston cost $50–70. Ride-hails pick up at the designated Rideshare zones outside baggage claim on the lower level.IAH has five terminals (A–E) connected by an underground tunnel with trams. Terminal D handles international arrivals. Rental car agencies are in a consolidated facility adjacent to Terminal C; a free IAH Connector bus runs between terminals and the rental car center. The Galleria / Uptown area costs $35–50 by ride-hail.

Humid subtropical climate. Hot, humid, and wet for much of the year. Summers are brutal (33–38°C) with high humidity and near-daily afternoon thunderstorms. Severe storms with hail and high winds regularly cause ground stops from April through September. Houston's flooding risk is significant. Heavy rain events, including tropical system remnants, have flooded airport roads, cutting off surface access even when the airport itself remains operational.

Winters are mild (5–18°C) with occasional ice storms. These are rare but highly disruptive when they occur. Hurricane season (June–November) requires monitoring for Gulf storms. October through March has the best flying weather.