Aviation kerosene climbed 11.76% on Thursday (Oct. 1), a price hike that directly affects ordinary Brazilians planning vacations or family travel. State-owned oil firm Petrobras raised distributor prices from R$ 5.585 to R$ 6.242 per liter (around $1.15), pushing the cumulative increase since March to 74%, when fuel cost R$ 3.592, roughly the price of a small bottle of mineral water at a local bakery.

The adjustment hits travelers quickly because fuel now accounts for more than 45% of total airline operating expenses in Brazil, up from roughly 30% before the Middle East conflict, according to the Brazilian Airline Association (Abear). Filling an airliner fuel tank now consumes almost half of all ticket revenue collected on a typical domestic route. That cost surge is already showing up in consumer inflation: airfares jumped 9.82% in September in the IPCA-15 mid-month inflation index tracked by the Brazilian Institute of Geography and Statistics (IBGE).

Understand the mechanism: jet fuel is an internationally traded commodity, meaning its base price depends on global crude oil benchmarks and the US dollar rather than domestic price caps. Although Petrobras refines about 85% of the fuel consumed in Brazil, the company updates wholesale prices on the first day of every month to match import parity and shipping disruptions in the Strait of Hormuz, a maritime chokepoint responsible for 20% of global petroleum shipments.

Refinery price changes varied slightly across major hubs, rising 12% in Duque de Caxias near Rio de Janeiro and 11.6% at Guarulhos in Sao Paulo and Betim in Minas Gerais, according to G1. The October increase marks the third consecutive monthly rise after a 13.9% jump in September. For passengers shopping for year-end holiday flights, higher fuel bills mean finding discount fares will feel as tough as balancing a household grocery budget.