Chicago to Sydney (Mascot) (ORD–SYD) — Airlines, Schedules & Connections

US passport holders must obtain an Electronic Travel Authority (ETA) before boarding. Apply through the Australian ETA app (subclass 601). The ETA costs AUD 20, is valid for 12 months with multiple entries, and allows stays of up to 90 days per visit. Processing is usually instant. Passport must be valid for at least 6 months beyond the date of entry.

CTA Blue Line runs 24/7 from downtown Loop stations to O'Hare (45 min, $5). Pace buses serve suburbs. Ride-shares cost $35–55 from downtown depending on traffic; add 30+ minutes during rush hour on the Kennedy Expressway.Economy parking lots E/F connect via ATS people mover. Terminal 5 (international) is separate from Terminals 1–3; allow extra time for inter-terminal transfers.

Airport Link trains depart every 10 minutes to Central Station (13 min, AUD $20.10 with Opal). The station access fee makes this more expensive than typical Sydney transit. Taxis from International Terminal queue outside arrivals; metered fares to the CBD run AUD $45–65. Uber operates from a designated ride-share zone.Rental car companies have desks in both the international and domestic terminal precincts. A SkyBus operates to the CBD and several suburbs as a cheaper alternative to taxis (AUD $24–27).

Temperate oceanic climate. Summers (December–February) are warm and humid at 24–32°C with afternoon sea breezes and occasional severe thunderstorms that can cause extended ground stops. Winters (June–August) are mild and mostly dry at 8–17°C. Fog on winter mornings occasionally delays operations.

The airport faces its greatest disruption risk from summer thunderstorms and, less commonly, from east-coast lows bringing heavy rain and strong winds in autumn and winter. Pack layers for winter. Summer evenings can be surprisingly cool with sea breezes.